dm raid: fix address sanitizer warning in raid_resume

There is a KASAN warning in raid_resume when running the lvm test
lvconvert-raid.sh. The reason for the warning is that mddev->raid_disks
is greater than rs->raid_disks, so the loop touches one entry beyond
the allocated length.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-raid.c

@@ -3817,7 +3817,7 @@ static void attempt_restore_of_faulty_devices(struct raid_set *rs)
 
 	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
 
-	for (i = 0; i < mddev->raid_disks; i++) {
+	for (i = 0; i < rs->raid_disks; i++) {
 		r = &rs->dev[i].rdev;
 		/* HM FIXME: enhance journal device recovery processing */
 		if (test_bit(Journal, &r->flags))