ASoC: Fix passing platform_data to ac97 bus users and fix a leak

[The issue is an attempt to write the pdata without the AC97 device
allocated when using ac97.c - also added a comment in soc-core.c for the
special case for ac97. -- broonie]

Signed-off-by: Graham Gower <graham.gower@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/soc-core.c

@@ -1548,7 +1548,8 @@ int snd_soc_new_pcms(struct snd_soc_device *socdev, int idx, const char *xid)
 			mutex_unlock(&codec->mutex);
 			return ret;
 		}
-		if (card->dai_link[i].codec_dai->ac97_control) {
+		/* Check for codec->ac97 to handle the ac97.c fun */
+		if (card->dai_link[i].codec_dai->ac97_control && codec->ac97) {
 			snd_ac97_dev_add_pdata(codec->ac97,
 				card->dai_link[i].cpu_dai->ac97_pdata);
 		}