svn merge -c 1569789 merging from trunk to branch-2.4 to fix:HDFS-5961. OIV cannot load fsimages containing a symbolic link.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1569791 13f79535-47bb-0310-9956-ffa450edef68