leds: mlxreg: Use devm_mutex_init() for mutex initialization

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses mutex which was destroyed already
in module's remove() so use devm API instead.

Signed-off-by: George Stark <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/leds/leds-mlxreg.c

···
 {
 	struct mlxreg_core_platform_data *led_pdata;
 	struct mlxreg_led_priv_data *priv;
+	int err;
 
 	led_pdata = dev_get_platdata(&pdev->dev);
 	if (!led_pdata) {
···
 	if (!priv)
 		return -ENOMEM;
 
-	mutex_init(&priv->access_lock);
+	err = devm_mutex_init(&pdev->dev, &priv->access_lock);
+	if (err)
+		return err;
+
 	priv->pdev = pdev;
 	priv->pdata = led_pdata;
 
 	return mlxreg_led_config(priv);
-}
-
-static void mlxreg_led_remove(struct platform_device *pdev)
-{
-	struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
-
-	mutex_destroy(&priv->access_lock);
 }
 
 static struct platform_driver mlxreg_led_driver = {
···
 	    .name = "leds-mlxreg",
 	},
 	.probe = mlxreg_led_probe,
-	.remove_new = mlxreg_led_remove,
 };
 
 module_platform_driver(mlxreg_led_driver);