staging: ks7010: remove two fields of ks_wlan_private struct

This commit removes l2_dev and l2_fd fields of ks_wlan_private
struct because they are not being used at all.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>