sunvnet: vnet_port_remove must call unregister_netdev

The missing call to unregister_netdev() leaves the interface active
after the driver is unloaded by rmmod.

Signed-off-by: Dave Kleikamp <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/sun/sunvnet.c

···
 		dev_set_drvdata(&vdev->dev, NULL);
 
 		kfree(port);
+
+		unregister_netdev(vp->dev);
 	}
 	return 0;
 }