pinctrl: meson: amlogic-a4: Fix device node reference leak in aml_dt_node_to_map_pinmux()

The of_get_parent() function returns a device_node with an incremented
reference count.

Use the __free(device_node) cleanup attribute to ensure of_node_put()
is automatically called when pnode goes out of scope, fixing a
reference leak.

Fixes: 6e9be3a ("pinctrl: Add driver support for Amlogic SoCs")
Signed-off-by: Felix Gu <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

Author: outman119

drivers/pinctrl/meson/pinctrl-amlogic-a4.c

@@ -679,7 +679,6 @@ static int aml_dt_node_to_map_pinmux(struct pinctrl_dev *pctldev,
 				     unsigned int *num_maps)
 {
 	struct device *dev = pctldev->dev;
-	struct device_node *pnode;
 	unsigned long *configs = NULL;
 	unsigned int num_configs = 0;
 	struct property *prop;
@@ -693,7 +692,7 @@ static int aml_dt_node_to_map_pinmux(struct pinctrl_dev *pctldev,
 		return -ENOENT;
 	}
 
-	pnode = of_get_parent(np);
+	struct device_node *pnode __free(device_node) = of_get_parent(np);
 	if (!pnode) {
 		dev_info(dev, "Missing function node\n");
 		return -EINVAL;