au1000_eth: possible NULL dereference of aup->mii_bus->irq in au1000_probe()

aup->mii_bus->irq allocation may fail, prevent a dereference of NULL.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/au1000_eth.c

@@ -1157,6 +1157,9 @@ static struct net_device * au1000_probe(int port_num)
 	aup->mii_bus->name = "au1000_eth_mii";
 	snprintf(aup->mii_bus->id, MII_BUS_ID_SIZE, "%x", aup->mac_id);
 	aup->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
+	if (aup->mii_bus->irq == NULL)
+		goto err_out;
+
 	for(i = 0; i < PHY_MAX_ADDR; ++i)
 		aup->mii_bus->irq[i] = PHY_POLL;