ASoC: Fix leak of rtd in soc_bind_dai_link

If we fail to find a platform we simply return EPROBE_DEFER,
but we have allocated the rtd pointer. All error paths before
soc_add_pcm_runtime need to call soc_free_pcm_runtime first to
avoid leaking the rtd pointer. A suitable error path already
exists and is used else where in the function so simply use that
here as well.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -1056,7 +1056,7 @@ static int soc_bind_dai_link(struct snd_soc_card *card,
 	if (!rtd->platform) {
 		dev_err(card->dev, "ASoC: platform %s not registered\n",
 			dai_link->platform_name);
-		return -EPROBE_DEFER;
+		goto _err_defer;
 	}
 
 	soc_add_pcm_runtime(card, rtd);