net/mlx4_en: Use ethtool cmd->autoneg as a hint for ethtool set settings

Use cmd->autoneg as a user hint to decide what to set in ethtool set settings callback.
When cmd->autoneg == AUTONEG_ENABLE set according to ethtool->advertise otherwise,
set according to ethtool->speed.

Usage:
	- ethtool -s eth<x> speed 56000 autoneg off
	- ethtool -s eth<x> advertise 0x800000 autoneg on

While we're here:
	- Move proto_admin masking outcome check to be adjacent to the operation.
	- Move en_warn("port reset..") print to "port reset" block.

Fixes: 312df74c ("net/mlx4_en: mlx4_en_set_settings() always fails when autoneg is set")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>