arcnet: fix signed bug in probe function

probe_irq_off() returns the first irq found or if two irqs are found
then it returns the negative of the first irq found.  We can cast
dev->irq to an int so that the test for negative values works.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/arcnet/com20020-isa.c

@@ -90,14 +90,14 @@ static int __init com20020isa_probe(struct net_device *dev)
 		outb(0, _INTMASK);
 		dev->irq = probe_irq_off(airqmask);
 
-		if (dev->irq <= 0) {
+		if ((int)dev->irq <= 0) {
 			BUGMSG(D_INIT_REASONS, "Autoprobe IRQ failed first time\n");
 			airqmask = probe_irq_on();
 			outb(NORXflag, _INTMASK);
 			udelay(5);
 			outb(0, _INTMASK);
 			dev->irq = probe_irq_off(airqmask);
-			if (dev->irq <= 0) {
+			if ((int)dev->irq <= 0) {
 				BUGMSG(D_NORMAL, "Autoprobe IRQ failed.\n");
 				err = -ENODEV;
 				goto out;

drivers/net/arcnet/com90io.c

@@ -213,7 +213,7 @@ static int __init com90io_probe(struct net_device *dev)
 		outb(0, _INTMASK);
 		dev->irq = probe_irq_off(airqmask);
 
-		if (dev->irq <= 0) {
+		if ((int)dev->irq <= 0) {
 			BUGMSG(D_INIT_REASONS, "Autoprobe IRQ failed\n");
 			goto err_out;
 		}