usb: gadget: net2280: fix memory leak on probe error handling paths

Driver does not release memory for device on error handling paths in
net2280_probe() when gadget_release() is not registered yet.

The patch fixes the bug like in other similar drivers.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/gadget/udc/net2280.c

@@ -3781,8 +3781,10 @@ static int net2280_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return 0;
 
 done:
-	if (dev)
+	if (dev) {
 		net2280_remove(pdev);
+		kfree(dev);
+	}
 	return retval;
 }