ASoC: rcar: add ID check on rsnd_dai_get()

checking id in rsnd_dai_get() is good idea

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/sh/rcar/core.c

@@ -318,6 +318,9 @@ int rsnd_dai_id(struct rsnd_priv *priv, struct rsnd_dai *rdai)
 
 struct rsnd_dai *rsnd_dai_get(struct rsnd_priv *priv, int id)
 {
+	if ((id < 0) || (id >= rsnd_dai_nr(priv)))
+		return NULL;
+
 	return priv->rdai + id;
 }