[PATCH] IPoIB: fix module removal race

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>

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -1005,6 +1005,7 @@ static struct net_device *ipoib_add_port(const char *format,
 
 register_failed:
 	ib_unregister_event_handler(&priv->event_handler);
+	flush_scheduled_work();
 
 event_failed:
 	ipoib_dev_cleanup(priv->dev);
@@ -1057,6 +1058,7 @@ static void ipoib_remove_one(struct ib_device *device)
 
 	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);