LU-4154 lfsck: skip old lfsck test in DNE mode

LU-4154 lfsck: skip old lfsck test in DNE mode

The old e2fsck/lfsck tool will not be allowed to run on a DNE
filesystem. This patch updates generate_db() to pass master MDS
parameters only, so that the old lfsck does not corrupt it or
delete all of the files on other MDTs.
This patch also fixes a typo in run_lfsck_remote().

This patch is back-ported from the following one:
Lustre-commit: b5f3d6db9200e369a68284a8ef85a1205e5905e1
Lustre-change: http://review.whamcloud.com/8206

Test-Parameters: alwaysuploadlogs mdtcount=4 testlist=lfsck
Test-Parameters: alwaysuploadlogs mdtcount=1 testlist=lfsck

Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: I5590b20c1c0003dbb1975a254093724de22497d4
Reviewed-on: http://review.whamcloud.com/9176
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>