Update CHANGES.txt to reflect commit of MR-6273 to branch-2.7

(cherry picked from commit ecad1253b782070adc1d825af3ffd2e214823046)

hadoop-mapreduce-project/CHANGES.txt

@@ -229,10 +229,6 @@ Release 2.8.0 - UNRELEASED
     MAPREDUCE-5708. Duplicate String.format in YarnOutputFiles.getSpillFileForWrite.
     (Konstantin Weitz via devaraj)
 
-    MAPREDUCE-6273. HistoryFileManager should check whether summaryFile exists to 
-    avoid FileNotFoundException causing HistoryFileInfo into MOVE_FAILED state.
-    (zhihai xu via devaraj)
-
     MAPREDUCE-6204. TestJobCounters should use new properties instead of
     JobConf.MAPRED_TASK_JAVA_OPTS. (Sam Liu via ozawa)
 
@@ -390,6 +386,10 @@ Release 2.7.2 - UNRELEASED
     MAPREDUCE-6518. Set SO_KEEPALIVE on shuffle connections (Chang Li via
     jlowe)
 
+    MAPREDUCE-6273. HistoryFileManager should check whether summaryFile exists to 
+    avoid FileNotFoundException causing HistoryFileInfo into MOVE_FAILED state.
+    (zhihai xu via devaraj)
+
 Release 2.7.1 - 2015-07-06 
 
   INCOMPATIBLE CHANGES