block/dirty-bitmap: add bs link

Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState
parameter from bitmap APIs where possible.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com
[Rebased on top of block-copy. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
diff --git a/blockdev.c b/blockdev.c
index 7e12919..d77e809 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2178,7 +2178,7 @@
                                              common, common);
 
     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
-    bdrv_release_dirty_bitmap(state->bs, state->bitmap);
+    bdrv_release_dirty_bitmap(state->bitmap);
 }
 
 static void abort_prepare(BlkActionState *common, Error **errp)
@@ -2940,7 +2940,7 @@
     }
 
     if (release) {
-        bdrv_release_dirty_bitmap(bs, bitmap);
+        bdrv_release_dirty_bitmap(bitmap);
     }
 
     if (bitmap_bs) {
@@ -3072,7 +3072,7 @@
     bdrv_merge_dirty_bitmap(dst, anon, backup, errp);
 
  out:
-    bdrv_release_dirty_bitmap(bs, anon);
+    bdrv_release_dirty_bitmap(anon);
     return dst;
 }