ASoC: sst_platform: unregister sst card when being closed

Signed-off-by: Lu Guanqun <guanqun.lu@intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/mid-x86/sst_platform.c

@@ -271,6 +271,7 @@ static int sst_platform_close(struct snd_pcm_substream *substream)
 	str_id = stream->stream_info.str_id;
 	if (str_id)
 		ret_val = stream->sstdrv_ops->pcm_control->close(str_id);
+	unregister_sst_card(stream->sstdrv_ops);
 	kfree(stream->sstdrv_ops);
 	kfree(stream);
 	return ret_val;