ASoC: rsnd: fix OF node reference leak in rsnd_ssiu_probe()

rsnd_ssiu_probe() leaks an OF node reference obtained by
rsnd_ssiu_of_node(). The node reference is acquired but
never released across all return paths.

Fix it by declaring the device node with the __free(device_node)
cleanup construct to ensure automatic release when the variable goes
out of scope.

Fixes: 4e7788f ("ASoC: rsnd: add SSIU BUSIF support")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/20251112065709.1522-1-vulab@iscas.ac.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: ISCAS-Vulab

sound/soc/renesas/rcar/ssiu.c

@@ -509,7 +509,7 @@ void rsnd_parse_connect_ssiu(struct rsnd_dai *rdai,
 int rsnd_ssiu_probe(struct rsnd_priv *priv)
 {
 	struct device *dev = rsnd_priv_to_dev(priv);
-	struct device_node *node;
+	struct device_node *node __free(device_node) = rsnd_ssiu_of_node(priv);
 	struct rsnd_ssiu *ssiu;
 	struct rsnd_mod_ops *ops;
 	const int *list = NULL;
@@ -522,7 +522,6 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv)
 	 * see
 	 *	rsnd_ssiu_bufsif_to_id()
 	 */
-	node = rsnd_ssiu_of_node(priv);
 	if (node)
 		nr = rsnd_node_count(priv, node, SSIU_NAME);
 	else