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: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
 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)