HADOOP-6318. Move CHANGES.txt message to 0.21 section.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@829289 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -30,8 +30,6 @@ Trunk (unreleased changes)
     HADOOP-6326. Hundson runs should check for AspectJ warnings and report
     failure if any is present (cos)
 
-    HADOOP-6318. Upgrade to Avro 1.2.0.  (cutting)
-
   OPTIMIZATIONS
 
   BUG FIXES
@@ -1124,6 +1122,8 @@ Release 0.21.0 - Unreleased
     HADOOP-6327. FileContext tests should not use /tmp and should clean up
     files.  (Sanjay Radia via szetszwo)
 
+    HADOOP-6318. Upgrade to Avro 1.2.0.  (cutting)
+
 Release 0.20.2 - Unreleased
 
   NEW FEATURES