block: Fix double put in blk_integrity_unregister

 - kobject_del already puts the parent.

 - Set integrity profile to NULL to prevent stale data.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

---

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -375,7 +375,7 @@ void blk_integrity_unregister(struct gen
 
 	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
 	kobject_del(&bi->kobj);
-	kobject_put(&disk->dev.kobj);
 	kmem_cache_free(integrity_cachep, bi);
+	disk->integrity = NULL;
 }
 EXPORT_SYMBOL(blk_integrity_unregister);