MAPREDUCE-6032. Fix the non-unicode character in the change log in CHANGES.txt.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1618270 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -225,7 +225,7 @@ Release 2.6.0 - UNRELEASED
     MAPREDUCE-5999. Fix dead link in InputFormat javadoc (Akira AJISAKA via aw)
 
     MAPREDUCE-6032. Made MR jobs write job history files on the default FS when
-    the current context’s FS is different. (Benjamin Zhitomirsky via zjshen)
+    the current context's FS is different. (Benjamin Zhitomirsky via zjshen)
 
 Release 2.5.0 - UNRELEASED