YARN-1861. Fixed a bug in RM to reset leader-election on fencing that was causing both RMs to be stuck in standby mode when automatic failover is enabled. Contributed by Karthik Kambatla and Xuan Gong.
svn merge --ignore-ancestry -c 1594356 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1594359 13f79535-47bb-0310-9956-ffa450edef68