staging: rtl8723au: Pass a struct wlan_network to rtw_set_ssid()

There is no point copying the ssid out of struct wlan_network when we
can just pass on the whole struct.

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