backlight: pwm_bl: 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.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230308073945.2336302-11-u.kleine-koenig@pengutronix.de

Author: Uwe Kleine-König

drivers/video/backlight/pwm_bl.c

@@ -625,7 +625,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int pwm_backlight_remove(struct platform_device *pdev)
+static void pwm_backlight_remove(struct platform_device *pdev)
 {
 	struct backlight_device *bl = platform_get_drvdata(pdev);
 	struct pwm_bl_data *pb = bl_get_data(bl);
@@ -635,8 +635,6 @@ static int pwm_backlight_remove(struct platform_device *pdev)
 
 	if (pb->exit)
 		pb->exit(&pdev->dev);
-
-	return 0;
 }
 
 static void pwm_backlight_shutdown(struct platform_device *pdev)
@@ -690,7 +688,7 @@ static struct platform_driver pwm_backlight_driver = {
 		.of_match_table	= of_match_ptr(pwm_backlight_of_match),
 	},
 	.probe		= pwm_backlight_probe,
-	.remove		= pwm_backlight_remove,
+	.remove_new	= pwm_backlight_remove,
 	.shutdown	= pwm_backlight_shutdown,
 };