svn merge -c 1570252 meging from trunk to branch-2 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@1570255 13f79535-47bb-0310-9956-ffa450edef68