soc: atmel: fix device_node release in atmel_soc_device_init()

A device_node acquired via of_find_node_by_path() requires explicit
calls to of_node_put() when it is no longer needed to avoid leaking the
resource.

Instead of adding the missing calls to of_node_put() in all execution
paths, use the cleanup attribute for 'np' by means of the __free()
macro, which automatically calls of_node_put() when the variable goes
out of scope.

Fixes: 960ddf7 ("drivers: soc: atmel: Avoid calling at91_soc_init on non AT91 SoCs")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241031-soc-atmel-soc-cleanup-v2-1-73f2d235fd98@gmail.com
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

Author: javiercarrascocruz

drivers/soc/atmel/soc.c

@@ -399,7 +399,7 @@ static const struct of_device_id at91_soc_allowed_list[] __initconst = {
 
 static int __init atmel_soc_device_init(void)
 {
-	struct device_node *np = of_find_node_by_path("/");
+	struct device_node *np __free(device_node) = of_find_node_by_path("/");
 
 	if (!of_match_node(at91_soc_allowed_list, np))
 		return 0;