P2P: Do not consider the p2p_scan results after p2p_stop_find
If p2p_stop_find is issued after the p2p_scan request is triggered to
the host driver, the obtained scan results are also considered to update
the P2P peer entries. This is not always desired behavior, i.e., it can
be clearer if no P2P-DEVICE-FOUND events are generated based of that
final pending scan.