ASoC: atmel: Fix unlocked snd_pcm_stop() call

snd_pcm_stop() must be called in the PCM substream lock context.

Cc: <stable@vger.kernel.org>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/soc/atmel/atmel-pcm-dma.c b/sound/soc/atmel/atmel-pcm-dma.c
index 1d38fd0..d128265 100644
--- a/sound/soc/atmel/atmel-pcm-dma.c
+++ b/sound/soc/atmel/atmel-pcm-dma.c
@@ -81,7 +81,9 @@
 
 		/* stop RX and capture: will be enabled again at restart */
 		ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
+		snd_pcm_stream_lock(substream);
 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock(substream);
 
 		/* now drain RHR and read status to remove xrun condition */
 		ssc_readx(prtd->ssc->regs, SSC_RHR);