USB: atmel_usba_udc: fix freeing irq in usba_udc_remove()

Add a free_irq() call on vbus gpio when we remove udc so that the
vbus irq is properly released.

Signed-off-by: Rob Emanuele <[e-mail]>
Signed-off-by: Nicolas Ferre <[e-mail]>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/atmel_usba_udc.c

···
 		usba_ep_cleanup_debugfs(&usba_ep[i]);
 	usba_cleanup_debugfs(udc);
 
-	if (gpio_is_valid(udc->vbus_pin))
+	if (gpio_is_valid(udc->vbus_pin)) {
+		free_irq(gpio_to_irq(udc->vbus_pin), udc);
 		gpio_free(udc->vbus_pin);
+	}
 
 	free_irq(udc->irq, udc);
 	kfree(usba_ep);