net: tile: Use helpers from linux/etherdevice.h to check/set MAC

Use is_zero_ether_addr() to check for the MAC address being all zeros instead of
open coding the check.

Also use ether_addr_copy() instead of a manual memcpy() to set the
netdev->dev_addr.

Furthermore, get rid of a redundant assignment of netdev->addr_len. This is
already set by ether_setup() which is called in tile_net_setup().
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/tile/tilegx.c

@@ -2192,7 +2192,6 @@ static void tile_net_dev_init(const char *name, const uint8_t *mac)
 {
 	int ret;
 	int i;
-	int nz_addr = 0;
 	struct net_device *dev;
 	struct tile_net_priv *priv;
 
@@ -2223,15 +2222,10 @@ static void tile_net_dev_init(const char *name, const uint8_t *mac)
 	 * be done before the device is opened.  If the MAC is all zeroes,
 	 * we use a random address, since we're probably on the simulator.
 	 */
-	for (i = 0; i < 6; i++)
-		nz_addr |= mac[i];
-
-	if (nz_addr) {
-		memcpy(dev->dev_addr, mac, ETH_ALEN);
-		dev->addr_len = 6;
-	} else {
+	if (!is_zero_ether_addr(mac))
+		ether_addr_copy(dev->dev_addr, mac);
+	else
 		eth_hw_addr_random(dev);
-	}
 
 	/* Register the network device. */
 	ret = register_netdev(dev);