ASoC: fsl: fix build warning in fsl_dma

The previous patch to fsl_dma.c ("fix initialization of DMA buffers")
left behind an unused local variable that causes a build warning.
Signed-off-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/fsl/fsl_dma.c

@@ -297,7 +297,6 @@ static irqreturn_t fsl_dma_isr(int irq, void *dev_id)
 static int fsl_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;
 	static u64 fsl_dma_dmamask = DMA_BIT_MASK(36);
 	int ret;