PacketSender::send does not work properly

PacketSender::send has a switch to determine wether it is a link-level PDU or not. It is using pdu_type(), which returns the most specific PDUType. For example, if you give it a Dot11Deauthentication, then pdu_type() == PDU::DOT11_DEAUTH and it will not go to the PDU::DOT11 case. It will then fall back to the regular send which uses default_iface, resulting in unexpected behavior.

I think it should be using matches_flag instead.