ASoC: pxa: remove useless assignment

cppcheck warning:

sound/soc/pxa/mmp-pcm.c:207:10: style: Variable 'ret' is assigned a
value that is never used. [unreadVariable]
 int ret = 0, stream;
         ^
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210326215927.936377-8-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/pxa/mmp-pcm.c

@@ -204,7 +204,7 @@ static int mmp_pcm_new(struct snd_soc_component *component,
 {
 	struct snd_pcm_substream *substream;
 	struct snd_pcm *pcm = rtd->pcm;
-	int ret = 0, stream;
+	int ret, stream;
 
 	for (stream = 0; stream < 2; stream++) {
 		substream = pcm->streams[stream].substream;