[Misc] Replace /*! with /**. (#4823)

* replace

* blabla

* balbla

* blabla
Co-authored-by: Steve <ubuntu@ip-172-31-34-29.ap-northeast-1.compute.internal>

src/graph/sampling/randomwalks/node2vec_cpu.cc

-/*!
+/**
  *  Copyright (c) 2021 by Contributors
  * @file graph/sampling/node2vec_cpu.cc
  * @brief DGL sampler - CPU implementation of node2vec random walk with OpenMP

src/graph/sampling/randomwalks/node2vec_impl.h

-/*!
+/**
  *  Copyright (c) 2021 by Contributors
  * @file graph/sampling/node2vec_impl.h
  * @brief DGL sampler - templated implementation definition of node2vec random
@@ -25,7 +25,7 @@ namespace sampling {
 
 namespace impl {
 
-/*!
+/**
  * @brief Node2vec random walk.
  * @param hg The heterograph.
  * @param seeds A 1D array of seed nodes, with the type the source type of the

src/graph/sampling/randomwalks/node2vec_randomwalk.h

-/*!
+/**
  *  Copyright (c) 2021 by Contributors
  * @file graph/sampling/node2vec_randomwalk.cc
  * @brief DGL sampler - CPU implementation of node2vec random walk.
@@ -46,7 +46,7 @@ bool has_edge_between(const CSRMatrix &csr, dgl_id_t u, dgl_id_t v) {
     return std::find(u_succ, u_succ + size, v) != u_succ + size;
 }
 
-/*!
+/**
  * @brief Node2vec random walk step function
  * @param data The path generated so far, of type \c IdxType.
  * @param curr The last node ID generated.

src/graph/sampling/randomwalks/randomwalk_cpu.cc

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/sampling/randomwalk_cpu.cc
  * @brief DGL sampler - CPU implementation of metapath-based random walk with

src/graph/sampling/randomwalks/randomwalk_gpu.cu

-/*!
+/**
  *  Copyright (c) 2021-2022 by Contributors
  * @file graph/sampling/randomwalk_gpu.cu
  * @brief CUDA random walk sampleing

src/graph/sampling/randomwalks/randomwalk_with_restart_cpu.cc

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/sampling/randomwalk_with_restart_cpu.cc
  * @brief DGL sampler - CPU implementation of metapath-based random walk with

src/graph/sampling/randomwalks/randomwalks.cc

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/sampling/randomwalks.cc
  * @brief Dispatcher of different DGL random walks by device type

src/graph/sampling/randomwalks/randomwalks_cpu.h

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/sampler/generic_randomwalk_cpu.h
  * @brief DGL sampler - templated implementation definition of random walks on
@@ -28,7 +28,7 @@ namespace impl {
 
 namespace {
 
-/*!
+/**
  * @brief Generic Random Walk.
  * @param seeds A 1D array of seed nodes, with the type the source type of the
  * first edge type in the metapath. \param max_num_steps The maximum number of

src/graph/sampling/randomwalks/randomwalks_impl.h

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/sampling/randomwalks_impl.h
  * @brief DGL sampler - templated implementation definition of random walks
@@ -24,7 +24,7 @@ namespace sampling {
 
 namespace impl {
 
-/*!
+/**
  * @brief Random walk step function
  */
 template <typename IdxType>
@@ -35,7 +35,7 @@ using StepFunc = std::function<
         dgl_id_t,   // last node ID
         int64_t)>;  // # of steps
 
-/*!
+/**
  * @brief Get the node types traversed by the metapath.
  * @return A 1D array of shape (len(metapath) + 1,) with node type IDs.
  */
@@ -43,7 +43,7 @@ template <DGLDeviceType XPU, typename IdxType>
 TypeArray GetNodeTypesFromMetapath(
     const HeteroGraphPtr hg, const TypeArray metapath);
 
-/*!
+/**
  * @brief Metapath-based random walk.
  * @param hg The heterograph.
  * @param seeds A 1D array of seed nodes, with the type the source type of the
@@ -62,7 +62,7 @@ std::pair<IdArray, IdArray> RandomWalk(
     const HeteroGraphPtr hg, const IdArray seeds, const TypeArray metapath,
     const std::vector<FloatArray> &prob);
 
-/*!
+/**
  * @brief Metapath-based random walk with restart probability.
  * @param hg The heterograph.
  * @param seeds A 1D array of seed nodes, with the type the source type of the
@@ -82,7 +82,7 @@ std::pair<IdArray, IdArray> RandomWalkWithRestart(
     const HeteroGraphPtr hg, const IdArray seeds, const TypeArray metapath,
     const std::vector<FloatArray> &prob, double restart_prob);
 
-/*!
+/**
  * @brief Metapath-based random walk with stepwise restart probability.  Useful
  *        for PinSAGE-like models.
  * @param hg The heterograph.

src/graph/serialize/dglgraph_data.h

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/dglgraph_data.h
  * @brief Graph serialization header
@@ -56,7 +56,7 @@ class GraphData : public runtime::ObjectRef {
  public:
   DGL_DEFINE_OBJECT_REF_METHODS(GraphData, runtime::ObjectRef, GraphDataObject);
 
-  /*! @brief create a new GraphData reference */
+  /** @brief create a new GraphData reference */
   static GraphData Create() {
     return GraphData(std::make_shared<GraphDataObject>());
   }

src/graph/serialize/dglgraph_serialize.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/graph_serialize.cc
  * @brief Graph serialization implementation

src/graph/serialize/graph_serialize.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/graph_serialize.cc
  * @brief Graph serialization implementation

src/graph/serialize/graph_serialize.h

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/graph_serialize.h
  * @brief Graph serialization header
@@ -76,7 +76,7 @@ class StorageMetaData : public runtime::ObjectRef {
   DGL_DEFINE_OBJECT_REF_METHODS(
       StorageMetaData, runtime::ObjectRef, StorageMetaDataObject);
 
-  /*! @brief create a new StorageMetaData reference */
+  /** @brief create a new StorageMetaData reference */
   static StorageMetaData Create() {
     return StorageMetaData(std::make_shared<StorageMetaDataObject>());
   }

src/graph/serialize/heterograph_data.h

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/heterograph_data.h
  * @brief Graph serialization header
@@ -97,7 +97,7 @@ class HeteroGraphData : public runtime::ObjectRef {
   DGL_DEFINE_OBJECT_REF_METHODS(
       HeteroGraphData, runtime::ObjectRef, HeteroGraphDataObject);
 
-  /*! @brief create a new GraphData reference */
+  /** @brief create a new GraphData reference */
   static HeteroGraphData Create(
       HeteroGraphPtr gptr, List<Map<std::string, Value>> node_tensors,
       List<Map<std::string, Value>> edge_tensors, List<Value> ntype_names,
@@ -106,7 +106,7 @@ class HeteroGraphData : public runtime::ObjectRef {
         gptr, node_tensors, edge_tensors, ntype_names, etype_names));
   }
 
-  /*! @brief create an empty GraphData reference */
+  /** @brief create an empty GraphData reference */
   static HeteroGraphData Create() {
     return HeteroGraphData(std::make_shared<HeteroGraphDataObject>());
   }

src/graph/serialize/heterograph_serialize.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/heterograph_serialize.cc
  * @brief DGLHeteroGraph serialization implementation

src/graph/serialize/tensor_serialize.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file graph/serialize/tensor_serialize.cc
  * @brief Graph serialization implementation

src/graph/serialize/zerocopy_serializer.cc

-/*!
+/**
  *  Copyright (c) 2020-2022 by Contributors
  * @file graph/serailize/zerocopy_serializer.cc
  * @brief serializer implementation.

src/graph/shared_mem_manager.cc

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/shared_mem_manager.cc
  * @brief DGL sampler implementation

src/graph/shared_mem_manager.h

-/*!
+/**
  *  Copyright (c) 2018 by Contributors
  * @file graph/shared_mem_manager.cc
  * @brief DGL shared mem manager APIs

src/graph/subgraph.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file graph/subgraph.cc
  * @brief Functions for extracting subgraphs.