ARM: am79c961a: platform_get_irq() may return signed unnoticed

dev->irq is unsigned, platform_get_irq() may return signed unnoticed

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/arm/am79c961a.c b/drivers/net/arm/am79c961a.c
index ba6bd03..a637910 100644
--- a/drivers/net/arm/am79c961a.c
+++ b/drivers/net/arm/am79c961a.c
@@ -693,11 +693,15 @@
 	 * done by the ether bootp loader.
 	 */
 	dev->base_addr = res->start;
-	dev->irq = platform_get_irq(pdev, 0);
+	ret = platform_get_irq(pdev, 0);
+
+	if (ret < 0) {
+		ret = -ENODEV;
+		goto nodev;
+	}
+	dev->irq = ret;
 
 	ret = -ENODEV;
-	if (dev->irq < 0)
-		goto nodev;
 	if (!request_region(dev->base_addr, 0x18, dev->name))
 		goto nodev;