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/ns83820.c b/drivers/net/ns83820.c
index 6667e06..3e4040f 100644
--- a/drivers/net/ns83820.c
+++ b/drivers/net/ns83820.c
@@ -1251,7 +1251,7 @@
 	/*
 	 * Here's the list of available ethtool commands from other drivers:
 	 *	cmd->advertising =
-	 *	cmd->speed =
+	 *	ethtool_cmd_speed_set(cmd, ...)
 	 *	cmd->duplex =
 	 *	cmd->port = 0;
 	 *	cmd->phy_address =
@@ -1289,13 +1289,13 @@
 	cmd->duplex = fullduplex ? DUPLEX_FULL : DUPLEX_HALF;
 	switch (cfg / CFG_SPDSTS0 & 3) {
 	case 2:
-		cmd->speed = SPEED_1000;
+		ethtool_cmd_speed_set(cmd, SPEED_1000);
 		break;
 	case 1:
-		cmd->speed = SPEED_100;
+		ethtool_cmd_speed_set(cmd, SPEED_100);
 		break;
 	default:
-		cmd->speed = SPEED_10;
+		ethtool_cmd_speed_set(cmd, SPEED_10);
 		break;
 	}
 	cmd->autoneg = (tbicr & TBICR_MR_AN_ENABLE)