dm zoned: free dmz->ddev array in dmz_put_zoned_devices

Commit 4dba12881f ("dm zoned: support arbitrary number of devices")
made the pointers to additional zoned devices to be stored in a
dynamically allocated dmz->ddev array. However, this array is not freed.

Rename dmz_put_zoned_device to dmz_put_zoned_devices and fix it to
free the dmz->ddev array when cleaning up zoned device information.
Remove NULL assignment for all dmz->ddev elements and just free the
dmz->ddev array instead.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 4dba12881f ("dm zoned: support arbitrary number of devices")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-zoned-target.c

@@ -748,17 +748,16 @@ err:
 /*
  * Cleanup zoned device information.
  */
-static void dmz_put_zoned_device(struct dm_target *ti)
+static void dmz_put_zoned_devices(struct dm_target *ti)
 {
 	struct dmz_target *dmz = ti->private;
 	int i;
 
-	for (i = 0; i < dmz->nr_ddevs; i++) {
-		if (dmz->ddev[i]) {
+	for (i = 0; i < dmz->nr_ddevs; i++)
+		if (dmz->ddev[i])
 			dm_put_device(ti, dmz->ddev[i]);
-			dmz->ddev[i] = NULL;
-		}
-	}
+
+	kfree(dmz->ddev);
 }
 
 static int dmz_fixup_devices(struct dm_target *ti)
@@ -948,7 +947,7 @@ err_bio:
 err_meta:
 	dmz_dtr_metadata(dmz->metadata);
 err_dev:
-	dmz_put_zoned_device(ti);
+	dmz_put_zoned_devices(ti);
 err:
 	kfree(dmz->dev);
 	kfree(dmz);
@@ -978,7 +977,7 @@ static void dmz_dtr(struct dm_target *ti)
 
 	bioset_exit(&dmz->bio_set);
 
-	dmz_put_zoned_device(ti);
+	dmz_put_zoned_devices(ti);
 
 	mutex_destroy(&dmz->chunk_lock);