There were no curly braces in this if condition so it always enabled full
duplex.

And ecmd->speed is an unsigned short so it is never equal to -1.  The
effect is that mii_ethtool_sset() fails with -EINVAL and an error is
printed to dmesg.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>