staging: rtl8723au: rtw_do_join23a(): Don't start scanning if network isn't found

Don't start running network scans if trying to connect to a network
not in our cache. Let the 802.11 stack do it's job instead.

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