downcase_rdata: advance all the way to the end of names
downcase_rdata: advance all the way to the end of names

    without this fix, we don't end up downcasing all of the name fields
    for record types that contain multiple names (e.g, SOA)

hstern/wdns,d4s/wdns,hstern/wdns,hstern/wdns,hstern/wdns,d4s/wdns,d4s/wdns