staging: rtl8723au: Do not xmit BSS Coexistence management action frames

The driver should not be issuing BSS Coexistence management action
frames when scanning. This isn't required by the spec, and if needed,
these should come from wpa_s instead.

Recommended by Johannes Berg.

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