ASoC: Revert duplicated code in SSM2602 driver

The Blackfin submission was done as a patch against a different tree
and contained a duplicate hunk which will cause us to loose track of the
substream pointers when shutting down.  Remove one of the duplicated
hunks.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/ssm2602.c

@@ -375,10 +375,6 @@ static void ssm2602_shutdown(struct snd_pcm_substream *substream,
 	struct snd_soc_codec *codec = socdev->card->codec;
 	struct ssm2602_priv *ssm2602 = codec->private_data;
 
-	if (ssm2602->master_substream == substream)
-		ssm2602->master_substream = ssm2602->slave_substream;
-
-	ssm2602->slave_substream = NULL;
 	/* deactivate */
 	if (!codec->active)
 		ssm2602_write(codec, SSM2602_ACTIVE, 0);