net: mv643xx_eth: use platform_get_irq() instead of platform_get_resource()

It is not recommened to use platform_get_resource(pdev, IORESOURCE_IRQ)
for requesting IRQ's resources any more, as they can be not ready yet in
case of DT-booting.

platform_get_irq() instead is a recommended way for getting IRQ even if
it was not retrieved earlier.

It also makes code simpler because we're getting "int" value right away
and no conversion from resource to int is required.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mv643xx_eth.c

@@ -3092,8 +3092,7 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
 	struct mv643xx_eth_private *mp;
 	struct net_device *dev;
 	struct phy_device *phydev = NULL;
-	struct resource *res;
-	int err;
+	int err, irq;
 
 	pd = dev_get_platdata(&pdev->dev);
 	if (pd == NULL) {
@@ -3189,9 +3188,10 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
 	timer_setup(&mp->rx_oom, oom_timer_wrapper, 0);
 
 
-	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	BUG_ON(!res);
-	dev->irq = res->start;
+	irq = platform_get_irq(pdev, 0);
+	if (WARN_ON(irq < 0))
+		return irq;
+	dev->irq = irq;
 
 	dev->netdev_ops = &mv643xx_eth_netdev_ops;