LU-1866 lfsck: LFSCK for namespace consistency (2)

LU-1866 lfsck: LFSCK for namespace consistency (2)

It is the second part of LFSCK 1.5 for namespace consistency
check and repair. It mainly implements the LFSCK namespace
component functionality lfsck_operations::lfsck_exec_dir:
for linkEA verification and repair.

The basic functionality is to find out missed linkEA entries
and add them to the object. It is also part of handling IGIF
objects upgrading.

Test-Parameters: envdefinitions=ENABLE_QUOTA=yes testlist=sanity-lfsck

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I9df2a1fddfa4b15838ecbdfb6279c240d01d0f95
Reviewed-on: http://review.whamcloud.com/4913
Tested-by: Hudson
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>