can: at91_can: 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: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230512212725.143824-2-u.kleine-koenig@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/at91_can.c

@@ -1346,7 +1346,7 @@ static int at91_can_probe(struct platform_device *pdev)
 	return err;
 }
 
-static int at91_can_remove(struct platform_device *pdev)
+static void at91_can_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
 	struct at91_priv *priv = netdev_priv(dev);
@@ -1362,8 +1362,6 @@ static int at91_can_remove(struct platform_device *pdev)
 	clk_put(priv->clk);
 
 	free_candev(dev);
-
-	return 0;
 }
 
 static const struct platform_device_id at91_can_id_table[] = {
@@ -1381,7 +1379,7 @@ MODULE_DEVICE_TABLE(platform, at91_can_id_table);
 
 static struct platform_driver at91_can_driver = {
 	.probe = at91_can_probe,
-	.remove = at91_can_remove,
+	.remove_new = at91_can_remove,
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.of_match_table = of_match_ptr(at91_can_dt_ids),