block: add a function to clear incoming live migration flags

This function will clear all BDRV_O_INCOMING flags.

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index b3117ef..c0c90f0 100644
--- a/block.c
+++ b/block.c
@@ -3624,6 +3624,15 @@
     }
 }
 
+void bdrv_clear_incoming_migration_all(void)
+{
+    BlockDriverState *bs;
+
+    QTAILQ_FOREACH(bs, &bdrv_states, list) {
+        bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING);
+    }
+}
+
 int bdrv_flush(BlockDriverState *bs)
 {
     Coroutine *co;