ASoC: nuc900-pcm: remove unused variable 'dai'

Remove unused variable 'dai' to eliminate below warning.

  CC      sound/soc/nuc900/nuc900-pcm.o
sound/soc/nuc900/nuc900-pcm.c: In function 'nuc900_dma_new':
sound/soc/nuc900/nuc900-pcm.c:321: warning: unused variable 'dai'
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/nuc900/nuc900-pcm.c

@@ -318,7 +318,6 @@ static u64 nuc900_pcm_dmamask = DMA_BIT_MASK(32);
 static int nuc900_dma_new(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_card *card = rtd->card->snd_card;
-	struct snd_soc_dai *dai = rtd->cpu_dai;
 	struct snd_pcm *pcm = rtd->pcm;
 
 	if (!card->dev->dma_mask)