cluster/dht: Create linkfile with file uid/gid

Currently, linkfile creation happens as root.

use uid/gid returned from _cbk (link/rename) to set the correct ownership of
the link files.

Change-Id: I5345cff193d5095442ca446fbe5ea05f2c2d86a3
Signed-off-by: shishir gowda <sgowda@redhat.com>
BUG: 884597
Reviewed-on: http://review.gluster.org/5024
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>