LU-6895 lfsck: conflict lu_dirent_attrs members

LU-6895 lfsck: conflict lu_dirent_attrs members

It is by wrong that the LUDA_UNKNOWN is defined the same value as
LUDA_UPGRADE.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I4067d7852166fab77df69736b3a160e9f67a6abc
Reviewed-on: http://review.whamcloud.com/16821
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>