staging: ks7010: use ether_addr_copy in ks_wlan_set_encode_ext

Instead of manually memcpy ethernet addresses use ether_addr_copy
function for this purpose.

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