YARN-2250. FairScheduler.findLowestCommonAncestorQueue returns null when queues not identical (Krisztian Horvath via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.5@1607874 13f79535-47bb-0310-9956-ffa450edef68