qdev: Provide qdev_get_bus_hotplug_handler()

Let's use a wrapper instead of looking it up manually. This function can
than be reused when we explicitly want to have the bus hotplug handler
(e.g. when the bus hotplug handler was overwritten by the machine
hotplug handler).

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190228122849.4296-4-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index ea4c1f6..17f09aa 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -281,6 +281,7 @@
 void qdev_init_nofail(DeviceState *dev);
 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
                                  int required_for_version);
+HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev);
 HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev);
 /**
  * qdev_get_hotplug_handler: Get handler responsible for device wiring