net: dsa: realtek: 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: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/realtek/realtek-smi.c

@@ -506,12 +506,12 @@ static int realtek_smi_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int realtek_smi_remove(struct platform_device *pdev)
+static void realtek_smi_remove(struct platform_device *pdev)
 {
 	struct realtek_priv *priv = platform_get_drvdata(pdev);
 
 	if (!priv)
-		return 0;
+		return;
 
 	dsa_unregister_switch(priv->ds);
 	if (priv->slave_mii_bus)
@@ -520,8 +520,6 @@ static int realtek_smi_remove(struct platform_device *pdev)
 	/* leave the device reset asserted */
 	if (priv->reset)
 		gpiod_set_value(priv->reset, 1);
-
-	return 0;
 }
 
 static void realtek_smi_shutdown(struct platform_device *pdev)
@@ -559,7 +557,7 @@ static struct platform_driver realtek_smi_driver = {
 		.of_match_table = realtek_smi_of_match,
 	},
 	.probe  = realtek_smi_probe,
-	.remove = realtek_smi_remove,
+	.remove_new = realtek_smi_remove,
 	.shutdown = realtek_smi_shutdown,
 };
 module_platform_driver(realtek_smi_driver);