Moving CHANGES.txt entry for MAPREDUCE-4742 to branch-2.7.

(cherry picked from commit bd0a9ba8e3b1c75dd2fc4cc65cb00c3e31d609ce)

hadoop-mapreduce-project/CHANGES.txt

@@ -12,8 +12,6 @@ Release 2.8.0 - UNRELEASED
 
   BUG FIXES
 
-    MAPREDUCE-4742. Fix typo in nnbench#displayUsage. (Liang Xie via ozawa)
-
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES
@@ -192,6 +190,8 @@ Release 2.7.0 - UNRELEASED
     MAPREDUCE-5657. [JDK8] Fix Javadoc errors caused by incorrect or illegal
     tags in doc comments. (Akira AJISAKA and Andrew Purtell via ozawa)
 
+    MAPREDUCE-4742. Fix typo in nnbench#displayUsage. (Liang Xie via ozawa)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES