thermal/of: Fix reference leak in thermal_of_cm_lookup()

In thermal_of_cm_lookup(), tr_np is obtained via of_parse_phandle(), but
never released.

Use the __free(device_node) cleanup attribute to automatically release
the node and fix the leak.

Fixes: 423de5b ("thermal/of: Fix cdev lookup in thermal_of_should_bind()")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20260124-thermal_of-v1-1-54d3416948cf@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: outman119

drivers/thermal/thermal_of.c

@@ -280,10 +280,10 @@ static bool thermal_of_cm_lookup(struct device_node *cm_np,
 				 struct cooling_spec *c)
 {
 	for_each_child_of_node_scoped(cm_np, child) {
-		struct device_node *tr_np;
 		int count, i;
 
-		tr_np = of_parse_phandle(child, "trip", 0);
+		struct device_node *tr_np __free(device_node) =
+			of_parse_phandle(child, "trip", 0);
 		if (tr_np != trip->priv)
 			continue;