LU-7349 lfsck: skip auto resume lfsck when mount

LU-7349 lfsck: skip auto resume lfsck when mount

Usually, if during the LFSCK running the server is umounted or
crashed, then when the server is mounted again, the LFSCK will
resume from the latest checkpoint automatically.

But if the server corruption is caused by the LFSCK, such auto
resuming LFSCK when mount may cause the server to crash again.
To avoid such trouble, introduce new server side mount option
"skip_lfsck" which will prevent unfinished LFSCK auto resuming
when mount.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I773dcde9dd239abe1e82127004ffef28ff1f1ae3
Reviewed-on: http://review.whamcloud.com/16972
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: Oleg Drokin <oleg.drokin@intel.com>