LU-5180 lfsck: linkea for orphan

To make the fid2path tools can work against any client visible
object, the LFSCK will generate linkEA not only for the orphan
under the directory /ROOT/.lustre/lost+found/MDTxxxx/ but also
for the objects ".lustre" and ".lustre/lost+found".

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: Ibf957e8e2ec93d0f8f8a7cf1ac45706fb79a41db
Reviewed-on: http://review.whamcloud.com/10733
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>