usb: renesas_usbhs: 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: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20230517230239.187727-89-u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/renesas_usbhs/common.c

@@ -762,7 +762,7 @@ static int usbhs_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int usbhs_remove(struct platform_device *pdev)
+static void usbhs_remove(struct platform_device *pdev)
 {
 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
 
@@ -780,8 +780,6 @@ static int usbhs_remove(struct platform_device *pdev)
 	usbhs_mod_remove(priv);
 	usbhs_fifo_remove(priv);
 	usbhs_pipe_remove(priv);
-
-	return 0;
 }
 
 static __maybe_unused int usbhsc_suspend(struct device *dev)
@@ -826,7 +824,7 @@ static struct platform_driver renesas_usbhs_driver = {
 		.of_match_table = usbhs_of_match,
 	},
 	.probe		= usbhs_probe,
-	.remove		= usbhs_remove,
+	.remove_new	= usbhs_remove,
 };
 
 module_platform_driver(renesas_usbhs_driver);