HBASE-9783 o.a.h.h.r.HRegion.mutateRow() with non-existent CF cause NPE (Aditya Kishore)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1534365 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/0.94' into 0.94-gd
Merge remote branch 'origin/0.94-gd' into fb-YAHOO-323-0.94-gd