isdn/act2000: fix major bug. clean irq handler.

* invert sense of request_irq() test.  otherwise we will always fail,
  when IRQ is available.

* no need to use 'irq' function arg, its stored in a data struct already
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/isdn/act2000/act2000_isa.c

@@ -61,7 +61,7 @@ act2000_isa_detect(unsigned short portbase)
 }
 
 static irqreturn_t
-act2000_isa_interrupt(int irq, void *dev_id)
+act2000_isa_interrupt(int dummy, void *dev_id)
 {
         act2000_card *card = dev_id;
         u_char istatus;
@@ -80,7 +80,7 @@ act2000_isa_interrupt(int irq, void *dev_id)
                 printk(KERN_WARNING "act2000: errIRQ\n");
         }
 	if (istatus)
-		printk(KERN_DEBUG "act2000: ?IRQ %d %02x\n", irq, istatus);
+		printk(KERN_DEBUG "act2000: ?IRQ %d %02x\n", card->irq, istatus);
 	return IRQ_HANDLED;
 }
 
@@ -131,6 +131,8 @@ act2000_isa_enable_irq(act2000_card * card)
 int
 act2000_isa_config_irq(act2000_card * card, short irq)
 {
+	int old_irq;
+
         if (card->flags & ACT2000_FLAGS_IVALID) {
                 free_irq(card->irq, card);
         }
@@ -139,8 +141,10 @@ act2000_isa_config_irq(act2000_card * card, short irq)
         if (!irq)
                 return 0;
 
-	if (!request_irq(irq, &act2000_isa_interrupt, 0, card->regname, card)) {
+	old_irq = card->irq;
 	card->irq = irq;
+	if (request_irq(irq, &act2000_isa_interrupt, 0, card->regname, card)) {
+		card->irq = old_irq;
 		card->flags |= ACT2000_FLAGS_IVALID;
                 printk(KERN_WARNING
                        "act2000: Could not request irq %d\n",irq);