xilinx ll_temac: use eth_hw_addr_random() instead of random_ether_addr()

Use eth_hw_addr_random() instead of calling random_ether_addr()
to set addr_assign_type correctly to NET_ADDR_RANDOM.

Reset the state to NET_ADDR_PERM as soon as the MAC get
changed via .ndo_set_mac_address.

v2: reworked to prevent using an extra variable
Signed-off-by: NDanny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/ll_temac_main.c

@@ -327,7 +327,9 @@ static int temac_set_mac_address(struct net_device *ndev, void *address)
 		memcpy(ndev->dev_addr, address, ETH_ALEN);
 
 	if (!is_valid_ether_addr(ndev->dev_addr))
-		random_ether_addr(ndev->dev_addr);
+		eth_hw_addr_random(ndev);
+	else
+		dev->addr_assign_type &= ~NET_ADDR_RANDOM;
 
 	/* set up unicast MAC address filter set its mac address */
 	mutex_lock(&lp->indirect_mutex);