ASoC: meson: axg-card: fix null pointer dereference in clean up

When using modern dai_link style, we must first make sure the
struct snd_soc_dai_link_component exists before accessing its members.

In case of early probe deferral, some of the '.cpus' or '.codecs' may not
have been allocated yet. Check this before calling of_node_put() on the
structure member.

Fixes: c84836d7 ("ASoC: meson: axg-card: use modern dai_link style")
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/meson/axg-card.c

@@ -115,9 +115,11 @@ static void axg_card_clean_references(struct axg_card *priv)
 
 	if (card->dai_link) {
 		for_each_card_prelinks(card, i, link) {
-			of_node_put(link->cpus->of_node);
+			if (link->cpus)
+				of_node_put(link->cpus->of_node);
 			for_each_link_codecs(link, j, codec)
-				of_node_put(codec->of_node);
+				if (codec)
+					of_node_put(codec->of_node);
 		}
 	}