ALSA: pxa2xx: Replace BUG() with snd_BUG()

BUG() used in the driver is just to spit the stack trace on buggy
points, not really needed to stop the whole operation.  For that
purpose, it'd be more convenient to use snd_BUG() instead.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/arm/pxa2xx-ac97-lib.c

@@ -208,7 +208,7 @@ bool pxa2xx_ac97_try_warm_reset(struct snd_ac97 *ac97)
 		pxa_ac97_warm_pxa3xx();
 	else
 #endif
-		BUG();
+		snd_BUG();
 
 	while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
 		mdelay(1);
@@ -245,7 +245,7 @@ bool pxa2xx_ac97_try_cold_reset(struct snd_ac97 *ac97)
 		pxa_ac97_cold_pxa3xx();
 	else
 #endif
-		BUG();
+		snd_BUG();
 
 	while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--)
 		mdelay(1);