batman-adv: 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.

Remove dev_addr in interface_setup(), it's not needed anymore.

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

v2: use bitops, adapt to eth_hw_addr_random()
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/batman-adv/soft-interface.c

@@ -541,6 +541,7 @@ static int interface_set_mac_addr(struct net_device *dev, void *p)
 	}
 
 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+	dev->addr_assign_type &= ~NET_ADDR_RANDOM;
 	return 0;
 }
 
@@ -783,7 +784,6 @@ static const struct net_device_ops bat_netdev_ops = {
 static void interface_setup(struct net_device *dev)
 {
 	struct bat_priv *priv = netdev_priv(dev);
-	char dev_addr[ETH_ALEN];
 
 	ether_setup(dev);
 
@@ -800,8 +800,7 @@ static void interface_setup(struct net_device *dev)
 	dev->hard_header_len = BAT_HEADER_LEN;
 
 	/* generate random address */
-	random_ether_addr(dev_addr);
-	memcpy(dev->dev_addr, dev_addr, ETH_ALEN);
+	eth_hw_addr_random(dev);
 
 	SET_ETHTOOL_OPS(dev, &bat_ethtool_ops);