leds: max5970: Fix unreleased fwnode_handle in probe function

An object initialized via device_get_named_child_node() requires calls
to fwnode_handle_put() when it is no longer required to avoid leaking
memory.

Add the automatic cleanup facility for 'led_node' to ensure that
fwnode_handle_put() is called in all execution paths.

Fixes: 736214b ("leds: max5970: Add support for max5970")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241031-max5970-of_node_put-v2-1-0ffe1f1d3bc9@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: javiercarrascocruz

drivers/leds/leds-max5970.c

@@ -45,7 +45,7 @@ static int max5970_led_set_brightness(struct led_classdev *cdev,
 
 static int max5970_led_probe(struct platform_device *pdev)
 {
-	struct fwnode_handle *led_node, *child;
+	struct fwnode_handle *child;
 	struct device *dev = &pdev->dev;
 	struct regmap *regmap;
 	struct max5970_led *ddata;
@@ -55,7 +55,8 @@ static int max5970_led_probe(struct platform_device *pdev)
 	if (!regmap)
 		return -ENODEV;
 
-	led_node = device_get_named_child_node(dev->parent, "leds");
+	struct fwnode_handle *led_node __free(fwnode_handle) =
+		device_get_named_child_node(dev->parent, "leds");
 	if (!led_node)
 		return -ENODEV;