net: tc35815: Use pci_dev_id() to simplify the code

PCI core API pci_dev_id() can be used to get the BDF number for a pci
device. We don't need to compose it manually. Use pci_dev_id() to
simplify the code a little bit.
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/toshiba/tc35815.c

@@ -667,8 +667,7 @@ static int tc_mii_init(struct net_device *dev)
 	lp->mii_bus->name = "tc35815_mii_bus";
 	lp->mii_bus->read = tc_mdio_read;
 	lp->mii_bus->write = tc_mdio_write;
-	snprintf(lp->mii_bus->id, MII_BUS_ID_SIZE, "%x",
-		 (lp->pci_dev->bus->number << 8) | lp->pci_dev->devfn);
+	snprintf(lp->mii_bus->id, MII_BUS_ID_SIZE, "%x", pci_dev_id(lp->pci_dev));
 	lp->mii_bus->priv = dev;
 	lp->mii_bus->parent = &lp->pci_dev->dev;
 	err = mdiobus_register(lp->mii_bus);