MAPREDUCE-5956. Made MR AM not use maxAttempts to determine if the current attempt is the last retry. Contributed by Wangda Tan.
svn merge --ignore-ancestry -c 1609649 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1609650 13f79535-47bb-0310-9956-ffa450edef68