isdn: hisax: Fix pnp_irq's error checking for setup_niccy

The pnp_irq() function returns -1 if an error occurs.
pnp_irq() error checking for zero is not correct.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hisax/niccy.c

@@ -261,7 +261,7 @@ int setup_niccy(struct IsdnCard *card)
 			card->para[1] = pnp_port_start(pnp_d, 0);
 			card->para[2] = pnp_port_start(pnp_d, 1);
 			card->para[0] = pnp_irq(pnp_d, 0);
-			if (!card->para[0] || !card->para[1] ||
+			if (card->para[0] == -1 || !card->para[1] ||
 			    !card->para[2]) {
 				printk(KERN_ERR "NiccyPnP:some resources are "
 				       "missing %ld/%lx/%lx\n",