svn merge -c 1570255 merging from branch-2 to branch-2.4 to fix:HDFS-5962. Mtime and atime are not persisted for symbolic links.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1570256 13f79535-47bb-0310-9956-ffa450edef68