[ALSA] trident - Shut up compile warnings

Trident driver
Shut up compile warnings about uninitialized variables.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/trident/trident_main.c b/sound/pci/trident/trident_main.c
index a09b0fb..b01c91b 100644
--- a/sound/pci/trident/trident_main.c
+++ b/sound/pci/trident/trident_main.c
@@ -472,6 +472,7 @@
 		break;
 	default:
 		snd_BUG();
+		return;
 	}
 
 	outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));