thermal/drivers/stm32: 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.

st_thermal_unregister() always returned zero, so convert it to return void
without any loss and then just drop the return from st_mmap_remove().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230616165641.1055854-1-u.kleine-koenig@pengutronix.de

drivers/thermal/st/st_thermal.c

@@ -227,14 +227,12 @@ int st_thermal_register(struct platform_device *pdev,
 }
 EXPORT_SYMBOL_GPL(st_thermal_register);
 
-int st_thermal_unregister(struct platform_device *pdev)
+void st_thermal_unregister(struct platform_device *pdev)
 {
 	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 
 	st_thermal_sensor_off(sensor);
 	thermal_zone_device_unregister(sensor->thermal_dev);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(st_thermal_unregister);
 

drivers/thermal/st/st_thermal.h

@@ -94,7 +94,7 @@ struct st_thermal_sensor {
 
 extern int st_thermal_register(struct platform_device *pdev,
 			       const struct of_device_id *st_thermal_of_match);
-extern int st_thermal_unregister(struct platform_device *pdev);
+extern void st_thermal_unregister(struct platform_device *pdev);
 extern const struct dev_pm_ops st_thermal_pm_ops;
 
 #endif /* __STI_RESET_SYSCFG_H */

drivers/thermal/st/st_thermal_memmap.c

@@ -172,9 +172,9 @@ static int st_mmap_probe(struct platform_device *pdev)
 	return st_thermal_register(pdev,  st_mmap_thermal_of_match);
 }
 
-static int st_mmap_remove(struct platform_device *pdev)
+static void st_mmap_remove(struct platform_device *pdev)
 {
-	return st_thermal_unregister(pdev);
+	st_thermal_unregister(pdev);
 }
 
 static struct platform_driver st_mmap_thermal_driver = {
@@ -184,7 +184,7 @@ static struct platform_driver st_mmap_thermal_driver = {
 		.of_match_table = st_mmap_thermal_of_match,
 	},
 	.probe		= st_mmap_probe,
-	.remove		= st_mmap_remove,
+	.remove_new	= st_mmap_remove,
 };
 
 module_platform_driver(st_mmap_thermal_driver);