staging: rtl8723au: ioctl_cfg80211.c: Use ether_addr_equal()

... and in one case use is_zero_ether_addr()

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>