usb: gadget/renesas_usb3: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart from
emitting a warning) and this typically results in resource leaks. To improve
here there is a quest to make the remove callback return void. In the first
step of this quest all drivers are converted to .remove_new() which already
returns void. Eventually after all drivers are converted, .remove_new() is
renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20230517230239.187727-40-u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/renesas_usb3.c

@@ -2653,7 +2653,7 @@ static void renesas_usb3_debugfs_init(struct renesas_usb3 *usb3,
 }
 
 /*------- platform_driver ------------------------------------------------*/
-static int renesas_usb3_remove(struct platform_device *pdev)
+static void renesas_usb3_remove(struct platform_device *pdev)
 {
 	struct renesas_usb3 *usb3 = platform_get_drvdata(pdev);
 
@@ -2669,8 +2669,6 @@ static int renesas_usb3_remove(struct platform_device *pdev)
 
 	__renesas_usb3_ep_free_request(usb3->ep0_req);
 	pm_runtime_disable(&pdev->dev);
-
-	return 0;
 }
 
 static int renesas_usb3_init_ep(struct renesas_usb3 *usb3, struct device *dev,
@@ -3015,7 +3013,7 @@ static SIMPLE_DEV_PM_OPS(renesas_usb3_pm_ops, renesas_usb3_suspend,
 
 static struct platform_driver renesas_usb3_driver = {
 	.probe		= renesas_usb3_probe,
-	.remove		= renesas_usb3_remove,
+	.remove_new	= renesas_usb3_remove,
 	.driver		= {
 		.name =	udc_name,
 		.pm		= &renesas_usb3_pm_ops,