ASoC: pxa: Use WARN_ON() instead of BUG_ON()

Use WARN_ON() and handle the error cases accordingly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/pxa/pxa2xx-i2s.c b/sound/soc/pxa/pxa2xx-i2s.c
index d5340a0..c0d648d 100644
--- a/sound/soc/pxa/pxa2xx-i2s.c
+++ b/sound/soc/pxa/pxa2xx-i2s.c
@@ -165,7 +165,8 @@
 {
 	struct snd_dmaengine_dai_dma_data *dma_data;
 
-	BUG_ON(IS_ERR(clk_i2s));
+	if (WARN_ON(IS_ERR(clk_i2s)))
+		return -EINVAL;
 	clk_prepare_enable(clk_i2s);
 	clk_ena = 1;
 	pxa_i2s_wait();