staging/et131x: use SET_ETHTOOL_OPS directly

using a wrapper around SET_ETHTOOL_OPS macro is not actually required,

remove and use SET_ETHTOOL_OPS directly.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>