Suricata

Issue 7129 introduced a counter to track events raise for unknown ethertypes. This results in 2 values tracking unknown ethertypes as this example from stats.log shows:

decoder.unknown_ethertype                                    | Total                     | 281
decoder.event.ethernet.unknown_ethertype                     | Total                     | 281

Remove the legacy counter -- decoder.unknown_ethertype -- and keep the event-based counter.