staging: rtl8188eu: Fix prefer ether_addr_copy() over memcpy()

This patch fixes "Prefer ether_addr_copy() over memcpy()
if the Ethernet addresses are __aligned(2)" in rtw_ap.c
Pahole showed that the addresses are aligned.

Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>