ASoC: AMD: remove unused ‘dma_buffer’

In acp_dma_hw_params(), 'dma_buffer' is initialized, but not used. So
remove it.

sound/soc/amd/acp-pcm-dma.c: In function ‘acp_dma_hw_params’:
sound/soc/amd/acp-pcm-dma.c:673:25: warning: variable ‘dma_buffer’ set but not used [-Wunused-but-set-variable]
  struct snd_dma_buffer *dma_buffer;

Cc: Maruthi Bayyavarapu <maruthi.bayyavarapu@amd.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/amd/acp-pcm-dma.c

@@ -670,13 +670,10 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
 {
 	int status;
 	uint64_t size;
-	struct snd_dma_buffer *dma_buffer;
 	struct page *pg;
 	struct snd_pcm_runtime *runtime;
 	struct audio_substream_data *rtd;
 
-	dma_buffer = &substream->dma_buffer;
-
 	runtime = substream->runtime;
 	rtd = runtime->private_data;