dm: trigger change uevent on rename

Insert a missing KOBJ_CHANGE notification when a device is renamed.

Cc: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index be730fd..9627fa0 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -332,6 +332,8 @@
 		dm_table_put(table);
 	}
 
+	dm_kobject_uevent(hc->md);
+
 	dm_put(hc->md);
 	up_write(&_hash_lock);
 	kfree(old_name);