[Fix] clang warnings (#1618)

Co-authored-by: Minjie Wang <wmjlyjemaine@gmail.com>

src/array/cpu/rowwise_topk.cc

@@ -26,7 +26,7 @@ inline PickFn<IdxType> GetTopkPickFn(int64_t k, NDArray weight, bool ascending)
               return wdata[data[i]] < wdata[data[j]];
             };
         } else {
-          compare_fn = [wdata, data] (IdxType i, IdxType j) {
+          compare_fn = [wdata] (IdxType i, IdxType j) {
               return wdata[i] < wdata[j];
             };
         }
@@ -36,7 +36,7 @@ inline PickFn<IdxType> GetTopkPickFn(int64_t k, NDArray weight, bool ascending)
               return wdata[data[i]] > wdata[data[j]];
             };
         } else {
-          compare_fn = [wdata, data] (IdxType i, IdxType j) {
+          compare_fn = [wdata] (IdxType i, IdxType j) {
               return wdata[i] > wdata[j];
             };
         }

src/graph/network.cc

@@ -31,7 +31,7 @@ namespace network {
 static void NaiveDeleter(DLManagedTensor* managed_tensor) {
   delete [] managed_tensor->dl_tensor.shape;
   delete [] managed_tensor->dl_tensor.strides;
-  delete [] managed_tensor->dl_tensor.data;
+  free(managed_tensor->dl_tensor.data);
   delete managed_tensor;
 }
 

src/graph/sampling/randomwalks/metapath_randomwalk.h

@@ -75,7 +75,7 @@ std::pair<dgl_id_t, bool> MetapathRandomWalkStep(
     return std::make_pair(-1, true);
 
   FloatArray prob_etype = prob[etype];
-  IdxType idx;
+  IdxType idx = 0;
   if (IsNullArray(prob_etype)) {
     // empty probability array; assume uniform
     idx = RandomEngine::ThreadLocal()->RandInt(size);

src/scheduler/scheduler.cc

@@ -90,7 +90,7 @@ std::vector<IdArray> DegreeBucketing(const IdArray& msg_ids, const IdArray& vids
     ret.push_back(std::move(mids));
     ret.push_back(std::move(mid_section));
 
-    return std::move(ret);
+    return ret;
 }
 
 template std::vector<IdArray> DegreeBucketing<int32_t>(const IdArray& msg_ids,
@@ -161,7 +161,7 @@ std::vector<IdArray> GroupEdgeByNodeDegree(const IdArray& uids,
   ret.push_back(std::move(new_eids));
   ret.push_back(std::move(sections));
 
-  return std::move(ret);
+  return ret;
 }
 
 template std::vector<IdArray> GroupEdgeByNodeDegree<int32_t>(