ALSA: Return proper error code at probe in sound/isa/*

Some drivers in sound/isa/* don't handle the error code properly
from snd_card_create().  This patch fixes these places.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/isa/gus/interwave.c b/sound/isa/gus/interwave.c
index e040c76..50e429a 100644
--- a/sound/isa/gus/interwave.c
+++ b/sound/isa/gus/interwave.c
@@ -626,7 +626,7 @@
 		free_irq(iwcard->irq, (void *)iwcard);
 }
 
-static struct snd_card *snd_interwave_card_new(int dev)
+static int snd_interwave_card_new(int dev, struct snd_card **cardp)
 {
 	struct snd_card *card;
 	struct snd_interwave *iwcard;
@@ -635,12 +635,13 @@
 	err = snd_card_create(index[dev], id[dev], THIS_MODULE,
 			      sizeof(struct snd_interwave), &card);
 	if (err < 0)
-		return NULL;
+		return err;
 	iwcard = card->private_data;
 	iwcard->card = card;
 	iwcard->irq = -1;
 	card->private_free = snd_interwave_free;
-	return card;
+	*cardp = card;
+	return 0;
 }
 
 static int __devinit snd_interwave_probe(struct snd_card *card, int dev)
@@ -779,9 +780,9 @@
 	struct snd_card *card;
 	int err;
 
-	card = snd_interwave_card_new(dev);
-	if (! card)
-		return -ENOMEM;
+	err = snd_interwave_card_new(dev, &card);
+	if (err < 0)
+		return err;
 
 	snd_card_set_dev(card, devptr);
 	if ((err = snd_interwave_probe(card, dev)) < 0) {
@@ -877,9 +878,9 @@
 	if (dev >= SNDRV_CARDS)
 		return -ENODEV;
 				
-	card = snd_interwave_card_new(dev);
-	if (! card)
-		return -ENOMEM;
+	res = snd_interwave_card_new(dev, &card);
+	if (res < 0)
+		return res;
 
 	if ((res = snd_interwave_pnp(dev, card->private_data, pcard, pid)) < 0) {
 		snd_card_free(card);