YARN-2945. Fixing the CHANGES.txt to have the right JIRA number.

(cherry picked from commit cf831565e8344523e1bd0eaf686ed56a2b48b920)

hadoop-yarn-project/CHANGES.txt

@@ -670,7 +670,7 @@ Release 2.7.0 - 2015-04-20
     YARN-2914. [YARN-1492] Potential race condition in Singleton implementation of 
     SharedCacheUploaderMetrics, CleanerMetrics, ClientSCMMetrics. (Varun Saxena via kasha)
 
-    YARN-2964. FSLeafQueue#assignContainer - document the reason for using both write and
+    YARN-2945. FSLeafQueue#assignContainer - document the reason for using both write and
     read locks. (Tsuyoshi Ozawa via kasha)
 
     YARN-2944. InMemorySCMStore can not be instantiated with ReflectionUtils#newInstance.