P2P: Re-start P2P operation if station mode scanning is stopped
There were couple of code paths that could end up stopping station mode
scanning without clearing sta_scan_pending. This could result in P2P
search getting stuck waiting for completion of station mode scan which
would never show up. Fix this by calling wpas_p2p_continue_after_scan()
in cases where station mode scans are stopped. This allows
sta_scan_pending to be cleared and P2P search operation continued.