ALSA: opti-miro: Fix missing semicolon

To fix a build error
  sound/isa/opti9xx/miro.c:1281: error: expected ';' before '}' token
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/opti9xx/miro.c

@@ -1277,7 +1277,7 @@ static int __devinit snd_miro_probe(struct device *devptr, unsigned int n)
 		if (mpu_port < 0) {
 			snd_card_free(card);
 			snd_printk(KERN_ERR "unable to find a free MPU401 port\n");
-			return -EBUSY
+			return -EBUSY;
 		}
 	}
 	if (miro->irq == SNDRV_AUTO_IRQ) {