dm raid: remove unused d variable

clang with W=1 reports
drivers/md/dm-raid.c:2212:15: error: variable
  'd' set but not used [-Werror,-Wunused-but-set-variable]
        unsigned int d;
                     ^
This variable is not used so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-raid.c

@@ -2209,7 +2209,6 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 {
 	int role;
-	unsigned int d;
 	struct mddev *mddev = &rs->md;
 	uint64_t events_sb;
 	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
@@ -2324,7 +2323,6 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 	 *    to provide capacity for redundancy or during reshape
 	 *    to add capacity to grow the raid set.
 	 */
-	d = 0;
 	rdev_for_each(r, mddev) {
 		if (test_bit(Journal, &rdev->flags))
 			continue;
@@ -2340,8 +2338,6 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 			if (test_bit(FirstUse, &r->flags))
 				rebuild_and_new++;
 		}
-
-		d++;
 	}
 
 	if (new_devs == rs->raid_disks || !rebuilds) {