staging: vt6656: Use ether_addr_copy() on vnt_private members.

staging: vt6656: Use ether_addr_copy() on vnt_private members.

This patch fixes checkpatch.pl warning:
WARNING: Prefer ether_addr_copy() over memcpy() if the Ethernet
addresses are __aligned(2)

current_net_addr and permanent_net_addr members of vnt_private alignment
is changed to at last 16 bits so that ether_addr_copy can be safely used
on them.

buf->data is of type ieee80211_cts which is already properly aligned.

Signed-off-by: Krzysztof Adamski <k@japko.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>