[NET]: Return more appropriate error from eth_validate_addr().

Paul Bolle wrote:
> http://bugzilla.kernel.org/show_bug.cgi?id=9923 would have been much easier to
> track down if eth_validate_addr() would somehow complain aloud if an address 
> is invalid. Shouldn't it make at least some noise?

I guess it should return -EADDRNOTAVAIL similar to eth_mac_addr()
when validation fails.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ethernet/eth.c

@@ -301,7 +301,7 @@ static int eth_change_mtu(struct net_device *dev, int new_mtu)
 static int eth_validate_addr(struct net_device *dev)
 {
 	if (!is_valid_ether_addr(dev->dev_addr))
-		return -EINVAL;
+		return -EADDRNOTAVAIL;
 
 	return 0;
 }