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

* replace

* blabla

* balbla

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

src/array/cpu/array_index_select.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/array_index_select.cc
  * @brief Array index select CPU implementation

src/array/cpu/array_nonzero.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/array_nonzero.cc
  * @brief Array nonzero CPU implementation

src/array/cpu/array_op_impl.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/array_op_impl.cc
  * @brief Array operator CPU implementation

src/array/cpu/array_pack.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/array_index_select.cc
  * @brief Array index select CPU implementation

src/array/cpu/array_repeat.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/array_repeat.cc
  * @brief Array repeat CPU implementation

src/array/cpu/array_scatter.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/array_scatter.cc
  * @brief Array scatter CPU implementation

src/array/cpu/array_sort.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/array_sort.cc
  * @brief Array sort CPU implementation

src/array/cpu/array_utils.h

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file dgl/array_utils.h
  * @brief Utility classes and functions for DGL arrays.
@@ -18,7 +18,7 @@
 namespace dgl {
 namespace aten {
 
-/*!
+/**
  * @brief A hashmap that maps each ids in the given array to new ids starting
  * from zero.
  *
@@ -109,7 +109,7 @@ class IdHashMap {
   phmap::flat_hash_map<IdType, IdType> oldv2newv_;
 };
 
-/*
+/**
  * @brief Hash type for building maps/sets with pairs as keys.
  */
 struct PairHash {

src/array/cpu/coo_coalesce.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/coo_coalesce.cc
  * @brief COO coalescing

src/array/cpu/coo_linegraph.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/coo_line_graph.cc
  * @brief COO LineGraph

src/array/cpu/coo_remove.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/coo_remove.cc
  * @brief COO matrix remove entries CPU implementation
@@ -17,7 +17,7 @@ namespace impl {
 
 namespace {
 
-/*! @brief COORemove implementation for COOMatrix with default consecutive edge
+/** @brief COORemove implementation for COOMatrix with default consecutive edge
  * IDs */
 template <DGLDeviceType XPU, typename IdType>
 void COORemoveConsecutive(
@@ -45,7 +45,7 @@ void COORemoveConsecutive(
   }
 }
 
-/*! @brief COORemove implementation for COOMatrix with shuffled edge IDs */
+/** @brief COORemove implementation for COOMatrix with shuffled edge IDs */
 template <DGLDeviceType XPU, typename IdType>
 void COORemoveShuffled(
     COOMatrix coo, IdArray entries, std::vector<IdType> *new_rows,

src/array/cpu/coo_sort.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/coo_sort.cc
  * @brief COO sorting

src/array/cpu/csr_get_data.cc

-/*!
+/**
  *  Copyright (c) 2021 by Contributors
  * @file array/cpu/csr_get_data.cc
  * @brief Retrieve entries of a CSR matrix

src/array/cpu/csr_mm.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/csr_mm.cc
  * @brief CSR Matrix Multiplication

src/array/cpu/csr_remove.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/coo_remove.cc
  * @brief CSR matrix remove entries CPU implementation

src/array/cpu/csr_sort.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/csr_sort.cc
  * @brief CSR sorting

src/array/cpu/csr_sum.cc

-/*!
+/**
  *  Copyright (c) 2019 by Contributors
  * @file array/cpu/csr_sum.cc
  * @brief CSR Summation

src/array/cpu/csr_to_simple.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/csr_to_simple.cc
  * @brief CSR sorting

src/array/cpu/csr_union.cc

-/*!
+/**
  *  Copyright (c) 2020 by Contributors
  * @file array/cpu/coo_sort.cc
  * @brief COO sorting

src/array/cpu/gather_mm.cc

- /*!
+ /**
  *  Copyright (c) 2020 by Contributors
  * @file kernel/cpu/gaher_mm.cc
  * @brief GatherMM C APIs and definitions.
@@ -9,7 +9,7 @@
 namespace dgl {
 namespace aten {
 
-/*! @brief Generalized SegmentMM. */
+/** @brief Generalized SegmentMM. */
 template <int XPU, typename IdType, typename DType>
 void SegmentMM(const NDArray A,
           const NDArray B,
@@ -27,7 +27,7 @@ void SegmentMMBackwardB(const NDArray A,
     LOG(FATAL) << "Unsupported CPU kernel for SegmentMMBackwardB.";
 }
 
-/*! @brief Generalized GatherMM. */
+/** @brief Generalized GatherMM. */
 template <int XPU, typename IdType, typename DType>
 void GatherMM(const NDArray A,
           const NDArray B,
@@ -37,7 +37,7 @@ void GatherMM(const NDArray A,
     LOG(FATAL) << "Unsupported CPU kernel for GatherMM.";
 }
 
-/*! @brief Generalized GatherMM_scatter. */
+/** @brief Generalized GatherMM_scatter. */
 template <int XPU, typename IdType, typename DType>
 void GatherMMScatter(const NDArray A,
           const NDArray B,