dm: improve shrinker debug names

Commit e33c267a ("mm: shrinkers: provide shrinkers with names")
chose some fairly bad names for DM's shrinkers.

Fixes: e33c267a ("mm: shrinkers: provide shrinkers with names")
Signed-off-by : Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-bufio.c

@@ -1833,7 +1833,7 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
 	c->shrinker.scan_objects = dm_bufio_shrink_scan;
 	c->shrinker.seeks = 1;
 	c->shrinker.batch = 0;
-	r = register_shrinker(&c->shrinker, "md-%s:(%u:%u)", slab_name,
+	r = register_shrinker(&c->shrinker, "dm-bufio:(%u:%u)",
 			      MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
 	if (r)
 		goto bad;

drivers/md/dm-zoned-metadata.c

@@ -2945,7 +2945,7 @@ int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev,
 	zmd->mblk_shrinker.seeks = DEFAULT_SEEKS;
 
 	/* Metadata cache shrinker */
-	ret = register_shrinker(&zmd->mblk_shrinker, "md-meta:(%u:%u)",
+	ret = register_shrinker(&zmd->mblk_shrinker, "dm-zoned-meta:(%u:%u)",
 				MAJOR(dev->bdev->bd_dev),
 				MINOR(dev->bdev->bd_dev));
 	if (ret) {