Since ipoib uses queue_delayed_work to run flush task on port state events,
it must flush scheduled work after unregistering the event handler.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
 
 register_failed:
        ib_unregister_event_handler(&priv->event_handler);
+       flush_scheduled_work();
 
 event_failed:
        ipoib_dev_cleanup(priv->dev);
 
        list_for_each_entry_safe(priv, tmp, dev_list, list) {
                ib_unregister_event_handler(&priv->event_handler);
+               flush_scheduled_work();
 
                unregister_netdev(priv->dev);
                ipoib_dev_cleanup(priv->dev);