fix

Change-Id: Icd732be883b7a9f08da2f154f00f153395b601d1

paddle/fluid/train/custom_trainer/feed/dataset/data_reader.cc

@@ -171,6 +171,7 @@ public:
                 if (line_len <= 0) {
                     continue;
                 }
+                DataItem data_item;
                 if (_parser->parse(buffer, line_len, data_item) == 0) {
                     VLOG(5) << "parse data: " << data_item.id << " " << data_item.data << ", filename: " << filepath << ", thread_num: " << thread_num << ", max_threads: " << max_threads;
                     if (writer == nullptr) {

paddle/fluid/train/custom_trainer/feed/io/shell.cc

@@ -165,14 +165,14 @@ static int shell_popen_fork_internal(
 
     if (child_end != child_std_end) {
         if (dup2(child_end, child_std_end) != child_std_end) {
-            return -1;
+            exit(127);
         }
         close(child_end);
     }
 
     close_open_fds_internal();
     if (execl("/bin/bash", "bash", "-c", real_cmd, NULL) < 0) {
-        return -1;
+        exit(127);
     }
     exit(127);
 #endif