[ALSA] Fix adding second dma channel

Modules: OPL3SA2 driver,GUS Classic driver

dma2 is a global array. sprintf below suggests there was a typo.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/isa/opl3sa2.c b/sound/isa/opl3sa2.c
index 9dc6b20..9d84319 100644
--- a/sound/isa/opl3sa2.c
+++ b/sound/isa/opl3sa2.c
@@ -723,7 +723,7 @@
 	}
 	sprintf(card->longname, "%s at 0x%lx, irq %d, dma %d",
 		card->shortname, chip->port, xirq, xdma1);
-	if (dma2 >= 0)
+	if (xdma2 >= 0)
 		sprintf(card->longname + strlen(card->longname), "&%d", xdma2);
 
 	return snd_card_register(card);