md-cluster: remove useless memset from gather_all_resync_info

This memset is not needed.  The lvb is already zeroed because
it was recently allocated by lockres_init, which uses kzalloc(),
and read_resync_info() doesn't need it to be zero anyway.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

drivers/md/md-cluster.c

@@ -777,7 +777,6 @@ static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 		if (ret == -EAGAIN) {
-			memset(bm_lockres->lksb.sb_lvbptr, '\0', LVB_SIZE);
 			s = read_resync_info(mddev, bm_lockres);
 			if (s) {
 				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",