don't eliminate nop node in getnext-memcpy elimination

mindspore/ccsrc/pre_activate/ascend/enhancer/getnext_memcpy_elimination.cc

@@ -56,9 +56,12 @@ const AnfNodePtr GetnextMemcpyElimination::Process(const FuncGraphPtr &graph, co
     return nullptr;
   }
 
-  // 3. next_node has only one input which is memcpy's output
+  // 3. next_node is not nop node and it has only one input which is memcpy's output
   for (auto &item : next_nodes) {
     auto next_node = item.first->cast<CNodePtr>();
+    if (opt::IsNopNode(next_node)) {
+      return nullptr;
+    }
     if (next_node->inputs().size() != 2) {
       MS_LOG(DEBUG) << "next node has more than one input";
       return nullptr;