Update CHANGES.txt: move HDFS-9626 and HDFS-9630 to the section of release 2.8

Change-Id: Ief7915e794d6862ca2c9d84f4188cb560d7dba95

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -211,8 +211,6 @@ Trunk (Unreleased)
     HDFS-9582. TestLeaseRecoveryStriped file missing Apache License header 
     and not well formatted. (umamahesh)
 
-    HDFS-9630. DistCp minor refactoring and clean up. (Kai Zheng via zhz)
-
   OPTIMIZATIONS
 
   BUG FIXES
@@ -408,9 +406,6 @@ Trunk (Unreleased)
     HDFS-9615. Fix variable name typo in DFSConfigKeys. (Ray Chiang via
     Arpit Agarwal)
 
-    HDFS-9626. TestBlockReplacement#testBlockReplacement fails occasionally.
-    (Xiao Chen via zhz)
-
     BREAKDOWN OF HDFS-7285 SUBTASKS AND RELATED JIRAS
 
       HDFS-7347. Configurable erasure coding policy for individual files and
@@ -1810,6 +1805,11 @@ Release 2.8.0 - UNRELEASED
     HDFS-9498. Move code that tracks blocks with future generation stamps
     to BlockManagerSafeMode. (Mingliang Liu via Arpit Agarwal)
 
+    HDFS-9626. TestBlockReplacement#testBlockReplacement fails occasionally.
+    (Xiao Chen via zhz)
+
+    HDFS-9630. DistCp minor refactoring and clean up. (Kai Zheng via zhz)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than