This device doesn't have fields to migrate. Be explicit
by using vmstate_qdev_no_state_to_migrate.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/nubus/mac-nubus-bridge.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/nubus/mac-nubus-bridge.c b/hw/nubus/mac-nubus-bridge.c
index 7c329300b8..ede36ccc5d 100644
--- a/hw/nubus/mac-nubus-bridge.c
+++ b/hw/nubus/mac-nubus-bridge.c
@@ -27,6 +27,7 @@ static void mac_nubus_bridge_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->desc = "Nubus bridge";
+    dc->vmsd = vmstate_qdev_no_state_to_migrate;
 }
 
 static const TypeInfo mac_nubus_bridge_info = {
-- 
2.21.3