fix epoch_done save

paddle/fluid/train/custom_trainer/feed/accessor/epoch_accessor.cc

@@ -49,12 +49,16 @@ namespace feed {
         set_status(EpochStatusFiled::CheckpointPathField, _last_checkpoint_path);
         set_status(EpochStatusFiled::DateField, format_timestamp(epoch_id, "%Y%m%d-%H%M"));
         set_status(EpochStatusFiled::InferenceBaseKeyField, _inference_base_model_key);
+        
+        auto* env = _trainer_context->environment.get();
+        if (env->is_master_node(EnvironmentRole::WORKER)) {
             if (epoch_id > _last_done_epoch_id) {
                 // 保留末尾1000数据
                 auto fs = _trainer_context->file_system.get();
                 std::string done_str = paddle::string::join_strings(_done_status, '\t');
                 fs->append_line(_done_file_path, done_str, 1000); 
             }
+        }
         return 0;
     }