LU-5519 lfsck: repair master LMV for striped directory

LU-5519 lfsck: repair master LMV for striped directory

If the master MDT-object of a striped directory lost its LMV EA,
then there may be some users have created some files under the
master MDT-object directly. Under such case, the LFSCK cannot
re-generate LMV EA for the master MDT-object, because we should
keep the existing files to be visible to client. Then the LFSCK
will mark the striped directory as read-only and keep it there
to be handled by administrator manually.

If nobody has created files under the master MDT-object of the
striped directory, then we will set the master LMV EA and
generate a new rescan (the striped directory) request that will
be handled later by the LFSCK instance on the MDT later.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I4d604cbd346c2cb044503f193ab4745e7fd2c2a2
Reviewed-on: http://review.whamcloud.com/11847
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>