dm raid: delete the redundant word 'that' in comment

Signed-off-by: Jilin Yuan <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-raid.c

···
 		 * of the "sync" directive.
 		 *
 		 * With reshaping capability added, we must ensure that
-		 * that the "sync" directive is disallowed during the reshape.
+		 * the "sync" directive is disallowed during the reshape.
 		 */
 		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
 			continue;