dm-raid: fix a race condition in request handling

raid_map calls pers->make_request, which missed the suspend check. Fix it with
the new md_handle_request API.

Fix: cc27b0c7(md: fix deadlock between mddev_suspend() and md_write_start())
Cc: Heinz Mauelshagen <heinzm@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

drivers/md/dm-raid.c

@@ -3238,7 +3238,7 @@ static int raid_map(struct dm_target *ti, struct bio *bio)
 	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
 		return DM_MAPIO_REQUEUE;
 
-	mddev->pers->make_request(mddev, bio);
+	md_handle_request(mddev, bio);
 
 	return DM_MAPIO_SUBMITTED;
 }