YARN-1873. Fixed TestDistributedShell failure when the test cases are out of order. Contributed by Mit Desai.
svn merge --ignore-ancestry -c 1582060 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582062 13f79535-47bb-0310-9956-ffa450edef68