drm/kmb: 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: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102165640.3307820-29-u.kleine-koenig@pengutronix.de

drivers/gpu/drm/kmb/kmb_drv.c

@@ -448,7 +448,7 @@ static const struct drm_driver kmb_driver = {
 	.minor = DRIVER_MINOR,
 };
 
-static int kmb_remove(struct platform_device *pdev)
+static void kmb_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct drm_device *drm = dev_get_drvdata(dev);
@@ -473,7 +473,6 @@ static int kmb_remove(struct platform_device *pdev)
 	/* Unregister DSI host */
 	kmb_dsi_host_unregister(kmb->kmb_dsi);
 	drm_atomic_helper_shutdown(drm);
-	return 0;
 }
 
 static int kmb_probe(struct platform_device *pdev)
@@ -621,7 +620,7 @@ static SIMPLE_DEV_PM_OPS(kmb_pm_ops, kmb_pm_suspend, kmb_pm_resume);
 
 static struct platform_driver kmb_platform_driver = {
 	.probe = kmb_probe,
-	.remove = kmb_remove,
+	.remove_new = kmb_remove,
 	.driver = {
 		.name = "kmb-drm",
 		.pm = &kmb_pm_ops,