net: stmmac: dwmac-rk: 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 (mostly) ignored
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.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c

@@ -1863,15 +1863,13 @@ static int rk_gmac_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int rk_gmac_remove(struct platform_device *pdev)
+static void rk_gmac_remove(struct platform_device *pdev)
 {
 	struct rk_priv_data *bsp_priv = get_stmmac_bsp_priv(&pdev->dev);
 
 	stmmac_dvr_remove(&pdev->dev);
 
 	rk_gmac_powerdown(bsp_priv);
-
-	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -1925,7 +1923,7 @@ MODULE_DEVICE_TABLE(of, rk_gmac_dwmac_match);
 
 static struct platform_driver rk_gmac_dwmac_driver = {
 	.probe  = rk_gmac_probe,
-	.remove = rk_gmac_remove,
+	.remove_new = rk_gmac_remove,
 	.driver = {
 		.name           = "rk_gmac-dwmac",
 		.pm		= &rk_gmac_pm_ops,