staging: ks7010: use ether_addr_copy() instead of custom copy

In order to achieve ethernet address copies, ether_addr_copy()
function exists. So just use it and avoid the byte by byte copy.
This increase readability.

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