ALSA: ps3: Use WARN_ON() instead of BUG_ON()

BUG_ON() is rather useless for debugging as it leads to panic().
Use WARN_ON() and handle the error cases accordingly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/ppc/snd_ps3.c b/sound/ppc/snd_ps3.c
index 8c7dcbe..ebb76f2 100644
--- a/sound/ppc/snd_ps3.c
+++ b/sound/ppc/snd_ps3.c
@@ -933,8 +933,10 @@
 	int i, ret;
 	u64 lpar_addr, lpar_size;
 
-	BUG_ON(!firmware_has_feature(FW_FEATURE_PS3_LV1));
-	BUG_ON(dev->match_id != PS3_MATCH_ID_SOUND);
+	if (WARN_ON(!firmware_has_feature(FW_FEATURE_PS3_LV1)))
+		return -ENODEV;
+	if (WARN_ON(dev->match_id != PS3_MATCH_ID_SOUND))
+		return -ENODEV;
 
 	the_card.ps3_dev = dev;