!8894 Remove return node checking for SuccDeeperSimple() including function.

From: @zh_qh
Reviewed-by: @stsuteng
Signed-off-by: @stsuteng

mindspore/core/ir/graph_utils.cc

@@ -34,18 +34,17 @@
 
 namespace mindspore {
 std::vector<AnfNodePtr> TopoSort(const AnfNodePtr &root, const SuccFunc &succ, const IncludeFunc &include) {
+  std::vector<AnfNodePtr> res;
+  if (root == nullptr) {
+    return res;
+  }
   size_t seen = NewSeenGeneration();
   std::deque<AnfNodePtr> todo(1024);
-  std::vector<AnfNodePtr> res;
   todo.clear();
   todo.push_back(root);
 
   while (!todo.empty()) {
     AnfNodePtr node = todo.back();
-    if (node == nullptr) {
-      todo.pop_back();
-      continue;
-    }
     if (node->extra_seen_ == seen) {  // We use extra_seen_ as finish flag
       todo.pop_back();
       continue;
@@ -65,10 +64,8 @@ std::vector<AnfNodePtr> TopoSort(const AnfNodePtr &root, const SuccFunc &succ, c
     node->seen_ = seen;
     if (incl == FOLLOW) {
       auto succs = succ(node);
-      (void)std::copy_if(succs.begin(), succs.end(), std::back_inserter(todo), [seen](const AnfNodePtr &next) {
-        return next != nullptr && next->seen_ != seen &&
-               (next->func_graph() == nullptr || next->func_graph()->get_return() != next);
-      });
+      (void)std::copy_if(succs.begin(), succs.end(), std::back_inserter(todo),
+                         [seen](const AnfNodePtr &next) { return next != nullptr && next->seen_ != seen; });
     } else if (incl > EXCLUDE) {  // Not NOFOLLOW or EXCLUDE
       MS_LOG(EXCEPTION) << "The result of include(node) must be one of: \"follow\", \"nofollow\", \"exclude\"";
     }