YARN-412. Fixed FifoScheduler to check hostname of a NodeManager rather than its host:port during scheduling which caused incorrect locality for containers. Contributed by Roger Hoover.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1467244 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9078-trunk-gd