HADOOP-14942. DistCp#cleanup() should check whether jobFS is null.

Contributed by Andras Bokor.

(cherry picked from commit f36cbc847560d53e7955ced9ce7ce2773c805793)

hadoop-tools/hadoop-distcp/src/main/java/org/apache/hadoop/tools/DistCp.java

@@ -453,10 +453,12 @@ public class DistCp extends Configured implements Tool {
 
   private synchronized void cleanup() {
     try {
-      if (metaFolder == null) return;
-
-      jobFS.delete(metaFolder, true);
-      metaFolder = null;
+      if (metaFolder != null) {
+        if (jobFS != null) {
+          jobFS.delete(metaFolder, true);
+        }
+        metaFolder = null;
+      }
     } catch (IOException e) {
       LOG.error("Unable to cleanup meta folder: " + metaFolder, e);
     }