optimize naming

Author: jacquesqiao

paddle/fluid/operators/listen_and_serv_op.cc

@@ -233,9 +233,9 @@ void ListenAndServOp::RunAsyncLoop(framework::Executor *executor,
   auto optimize_prepared = executor->Prepare(*program, block_list);
   std::unordered_map<std::string,
                      std::shared_ptr<framework::ExecutorPrepareContext>>
-      grad_to_prepared_block;
+      grad_to_prepared_ctx;
   for (size_t i = 0; i < block_list.size(); ++i) {
-    grad_to_prepared_block[id_to_grad[block_list[i]]] = optimize_prepared[i];
+    grad_to_prepared_ctx[id_to_grad[block_list[i]]] = optimize_prepared[i];
   }
 
   VLOG(3) << "RunAsyncLoop into while";
@@ -254,7 +254,7 @@ void ListenAndServOp::RunAsyncLoop(framework::Executor *executor,
         LOG(ERROR) << "Can not find server side var: " << recv_var_name;
         PADDLE_THROW("Can not find server side var");
       }
-      AsyncExecuteBlock(executor, grad_to_prepared_block[recv_var_name].get(),
+      AsyncExecuteBlock(executor, grad_to_prepared_ctx[recv_var_name].get(),
                         v.second->GetMutableLocalScope());
     }