usb: gadget: udc: net2280: do not rely on 'driver' argument

future patches will remove the extra 'driver'
argument to ->udc_stop(), in order to do that,
we must make sure that our UDC does not rely
on it first.

Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc/net2280.c

@@ -2446,11 +2446,9 @@ static int net2280_stop(struct usb_gadget *_gadget,
 	dev = container_of(_gadget, struct net2280, gadget);
 
 	spin_lock_irqsave(&dev->lock, flags);
-	stop_activity(dev, driver);
+	stop_activity(dev, NULL);
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	dev->driver = NULL;
-
 	net2280_led_active(dev, 0);
 
 	/* Disable full-speed test mode */
@@ -2460,8 +2458,8 @@ static int net2280_stop(struct usb_gadget *_gadget,
 	device_remove_file(&dev->pdev->dev, &dev_attr_function);
 	device_remove_file(&dev->pdev->dev, &dev_attr_queues);
 
-	ep_dbg(dev, "unregistered driver '%s'\n",
-			driver ? driver->driver.name : "");
+	ep_dbg(dev, "unregistered driver '%s'\n", dev->driver->driver.name);
+	dev->driver = NULL;
 
 	return 0;
 }