MAPREDUCE-4914. TestMiniMRDFSSort fails with openJDK7. Contributed by Brandon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1429638 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-4915. TestShuffleExceptionCount fails with open JDK7. Contributed by Brandon Li.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1429641 13f79535-47bb-0310-9956-ffa450edef68