ASoC: audio-graph-card: fix refcount leak of cpu_ep in __graph_for_each_link()

The of_get_next_child() returns a node with refcount incremented, and
decrements the refcount of prev. So in the error path of the while loop,
of_node_put() needs be called for cpu_ep.

Fixes: fce9b90c ("ASoC: audio-graph-card: cleanup DAI link loop method - step2")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/1670228127-13835-1-git-send-email-wangyufen@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/audio-graph-card.c

@@ -485,8 +485,10 @@ static int __graph_for_each_link(struct asoc_simple_priv *priv,
 			of_node_put(codec_ep);
 			of_node_put(codec_port);
 
-			if (ret < 0)
+			if (ret < 0) {
+				of_node_put(cpu_ep);
 				return ret;
+			}
 
 			codec_port_old = codec_port;
 		}