Updated the 2.6.2 final release date.

(cherry picked from commit a4a6b5b4b470b1e7a3c5e2d38433429c455bc709)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -812,7 +812,7 @@ Release 2.6.3 - UNRELEASED
 
   BUG FIXES
 
-Release 2.6.2 - 2015-10-21
+Release 2.6.2 - 2015-10-28
 
   INCOMPATIBLE CHANGES
 

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

@@ -1132,7 +1132,7 @@ Release 2.6.3 - UNRELEASED
 
   BUG FIXES
 
-Release 2.6.2 - 2015-10-21
+Release 2.6.2 - 2015-10-28
 
   INCOMPATIBLE CHANGES
 

hadoop-mapreduce-project/CHANGES.txt

@@ -291,7 +291,7 @@ Release 2.6.3 - UNRELEASED
     MAPREDUCE-6528. Memory leak for HistoryFileManager.getJobSummary()
     (Junping Du via jlowe)
 
-Release 2.6.2 - 2015-10-21
+Release 2.6.2 - 2015-10-28
 
   INCOMPATIBLE CHANGES
 

hadoop-yarn-project/CHANGES.txt

@@ -865,7 +865,7 @@ Release 2.6.3 - UNRELEASED
 
   BUG FIXES
 
-Release 2.6.2 - 2015-10-21
+Release 2.6.2 - 2015-10-28
 
   INCOMPATIBLE CHANGES