parallels: Assign bs->file->bs to file in parallels_co_get_block_status

Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Message-id: 1453780743-16806-7-git-send-email-famz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

block/parallels.c

@@ -274,6 +274,7 @@ static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
         return 0;
     }
 
+    *file = bs->file->bs;
     return (offset << BDRV_SECTOR_BITS) |
         BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 }