block: Assert that bdrv_release_dirty_bitmap succeeded

We use a loop over bs->dirty_bitmaps to make sure the caller is
only releasing a bitmap owned by bs. Let's also assert that in this case
the caller is releasing a bitmap that does exist.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-7-git-send-email-jsnow@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

block/dirty-bitmap.c

@@ -305,6 +305,9 @@ static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
             }
         }
     }
+    if (bitmap) {
+        abort();
+    }
 }
 
 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)