merge MAPREDUCE-4723 amendment from trunk. Fix JobHistory Event handling. (Contributed by Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1411293 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryEventHandler.java

@@ -601,7 +601,7 @@ public class JobHistoryEventHandler extends AbstractService
       setSummarySlotSeconds(summary, context.getJob(jobId).getAllCounters());
       break;
     default:
-      throw new YarnException("Invalid event type");
+      break;
     }
   }