ASoC: soc-pcm: cleanup cppcheck warning at dpcm_runtime_setup_be_chan()

This patch cleanups below cppcheck warning.

sound/soc/soc-pcm.c:1624:30: style: The scope of the variable 'codec_stream' can be reduced. [variableScope]
  struct snd_soc_pcm_stream *codec_stream;
                             ^
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87o8aozf28.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-pcm.c

@@ -1625,7 +1625,6 @@ static void dpcm_runtime_setup_be_chan(struct snd_pcm_substream *substream)
 
 	for_each_dpcm_be(fe, stream, dpcm) {
 		struct snd_soc_pcm_runtime *be = dpcm->be;
-		struct snd_soc_pcm_stream *codec_stream;
 		struct snd_soc_pcm_stream *cpu_stream;
 		struct snd_soc_dai *dai;
 		int i;
@@ -1648,7 +1647,8 @@ static void dpcm_runtime_setup_be_chan(struct snd_pcm_substream *substream)
 		 * DAIs connected to a single CPU DAI, use CPU DAI's directly
 		 */
 		if (be->num_codecs == 1) {
-			codec_stream = snd_soc_dai_get_pcm_stream(asoc_rtd_to_codec(be, 0), stream);
+			struct snd_soc_pcm_stream *codec_stream = snd_soc_dai_get_pcm_stream(
+				asoc_rtd_to_codec(be, 0), stream);
 
 			soc_pcm_hw_update_chan(hw, codec_stream);
 		}