LU-11310 ldiskfs: Repair support for SUSE 15 again

LU-11310 ldiskfs: Repair support for SUSE 15 again

A recent patch split ext4-htree-lock.patch out from the various
ext4-pdirop.patch, but this happened before various
files were copies and modified for extra sles15 support.

The patch makes the necessary checks to bring the
htree-lock split to sle15.

Fixes: 46ed28c0d10a ("LU-11310 ldiskfs: Repair support for SUSE 15 GA and SP1")
Fixes: 42880f9502ba ("LU-13054 ldiskfs: split htree_lock as separate patch")
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I464aaebc52d5b2b73fdd748c7d4dbbaf43f1ac49
Reviewed-on: https://review.whamcloud.com/38611
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>