Return Windows device name for given pcap device name.

def dev_from_pcapname(self, pcap_name):
        """Return Windows device name for given pcap device name."""
        try:
            return next(iface for iface in six.itervalues(self)
                        if iface.pcap_name == pcap_name)
        except (StopIteration, RuntimeError):
            raise ValueError("Unknown pypcap network interface %r" % pcap_name)