usb: r8a66597-hcd: 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>
Link: https://lore.kernel.org/r/20230517230239.187727-78-u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/r8a66597-hcd.c

@@ -2379,7 +2379,7 @@ static const struct dev_pm_ops r8a66597_dev_pm_ops = {
 #define R8A66597_DEV_PM_OPS	NULL
 #endif
 
-static int r8a66597_remove(struct platform_device *pdev)
+static void r8a66597_remove(struct platform_device *pdev)
 {
 	struct r8a66597		*r8a66597 = platform_get_drvdata(pdev);
 	struct usb_hcd		*hcd = r8a66597_to_hcd(r8a66597);
@@ -2390,7 +2390,6 @@ static int r8a66597_remove(struct platform_device *pdev)
 	if (r8a66597->pdata->on_chip)
 		clk_put(r8a66597->clk);
 	usb_put_hcd(hcd);
-	return 0;
 }
 
 static int r8a66597_probe(struct platform_device *pdev)
@@ -2511,7 +2510,7 @@ static int r8a66597_probe(struct platform_device *pdev)
 
 static struct platform_driver r8a66597_driver = {
 	.probe =	r8a66597_probe,
-	.remove =	r8a66597_remove,
+	.remove_new =	r8a66597_remove,
 	.driver		= {
 		.name = hcd_name,
 		.pm	= R8A66597_DEV_PM_OPS,