leds: max8997: fix attribute-creation race

Use the attribute groups of the led-class to create the mode attribute
during probe in order to avoid racing with userspace.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

drivers/leds/leds-max8997.c

@@ -229,6 +229,12 @@ static ssize_t max8997_led_store_mode(struct device *dev,
 
 static DEVICE_ATTR(mode, 0644, max8997_led_show_mode, max8997_led_store_mode);
 
+static struct attribute *max8997_attrs[] = {
+	&dev_attr_mode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(max8997);
+
 static int max8997_led_probe(struct platform_device *pdev)
 {
 	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
@@ -253,6 +259,7 @@ static int max8997_led_probe(struct platform_device *pdev)
 	led->cdev.brightness_set = max8997_led_brightness_set;
 	led->cdev.flags |= LED_CORE_SUSPENDRESUME;
 	led->cdev.brightness = 0;
+	led->cdev.groups = max8997_groups;
 	led->iodev = iodev;
 
 	/* initialize mode and brightness according to platform_data */
@@ -281,14 +288,6 @@ static int max8997_led_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	ret = device_create_file(led->cdev.dev, &dev_attr_mode);
-	if (ret != 0) {
-		dev_err(&pdev->dev,
-			"failed to create file: %d\n", ret);
-		led_classdev_unregister(&led->cdev);
-		return ret;
-	}
-
 	return 0;
 }
 
@@ -296,7 +295,6 @@ static int max8997_led_remove(struct platform_device *pdev)
 {
 	struct max8997_led *led = platform_get_drvdata(pdev);
 
-	device_remove_file(led->cdev.dev, &dev_attr_mode);
 	led_classdev_unregister(&led->cdev);
 
 	return 0;