arc_emac: drop redundant mac address check

Checking if MAC address is valid using is_valid_ether_addr() is already done in
of_get_mac_address(). While at it, reorganize checking so it matches checks in
other drivers.
Signed-off-by: Luka Perkov <luka@openwrt.org>
CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/arc/emac_main.c

@@ -725,10 +725,10 @@ static int arc_emac_probe(struct platform_device *pdev)
 	/* Get MAC address from device tree */
 	mac_addr = of_get_mac_address(pdev->dev.of_node);
 
-	if (!mac_addr || !is_valid_ether_addr(mac_addr))
-		eth_hw_addr_random(ndev);
-	else
+	if (mac_addr)
 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
+	else
+		eth_hw_addr_random(ndev);
 
 	dev_info(&pdev->dev, "MAC address is now %pM\n", ndev->dev_addr);