pch_gbe: ethtool cannot change parameters when link is down

When attempting to change e.g. the advertising mask when the link is down
ecmd->speed is -1 causing mii_ethtool_sset() to bail out.

This bug bit when connecting to a gigabit switch through a 4-pin (industrial)
cable, since link negotiation would not complete (both endpoints claimed to
be gigabit-capable, but this is not possible with only 4 pins).
Any attempt to fix this by setting autonegation to not offer 1000Mbps
failed as the setting would not be accepted while the link was still down...

Set ecmd->speed to SPEED_1000 to satisfy mii_ethtool_sset()
(the actual value of ecmd->speed doesn't matter as long as it is valid,
since a re-negotation is forced afterwards).
Signed-off-by: Anders Larsen <al@alarsen.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_ethtool.c

@@ -118,6 +118,7 @@ static int pch_gbe_set_settings(struct net_device *netdev,
 	 * filled by get_settings() on a down link, speed is -1: */
 	if (speed == UINT_MAX) {
 		speed = SPEED_1000;
+		ethtool_cmd_speed_set(ecmd, speed);
 		ecmd->duplex = DUPLEX_FULL;
 	}
 	ret = mii_ethtool_sset(&adapter->mii, ecmd);