ethtool: cosmetic: Use ethtool ethtool_cmd_speed API

This updates the network drivers so that they don't access the
ethtool_cmd::speed field directly, but use ethtool_cmd_speed()
instead.

For most of the drivers, these changes are purely cosmetic and don't
fix any problem, such as for those 1GbE/10GbE drivers that indirectly
call their own ethtool get_settings()/mii_ethtool_gset(). The changes
are meant to enforce code consistency and provide robustness with
future larger throughputs, at the expense of a few CPU cycles for each
ethtool operation.

All drivers compiled with make allyesconfig ion x86_64 have been
updated.

Tested: make allyesconfig on x86_64 + e1000e/bnx2x work
Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/mlx4/en_ethtool.c b/drivers/net/mlx4/en_ethtool.c
index be4a9e0..2e858e4 100644
--- a/drivers/net/mlx4/en_ethtool.c
+++ b/drivers/net/mlx4/en_ethtool.c
@@ -265,10 +265,10 @@
 
 	trans_type = priv->port_state.transciver;
 	if (netif_carrier_ok(dev)) {
-		cmd->speed = priv->port_state.link_speed;
+		ethtool_cmd_speed_set(cmd, priv->port_state.link_speed);
 		cmd->duplex = DUPLEX_FULL;
 	} else {
-		cmd->speed = -1;
+		ethtool_cmd_speed_set(cmd, -1);
 		cmd->duplex = -1;
 	}