Bug#952660: src:linux: macvlan multicast/broadcast regression in stretch

[Tero Marttila]

This seems to also affect keepalived `use_vmac` configurations, where 
the keepalived VIPs are configured on macvlan interfaces. After a 
stretch kernel update from 4.9.0-11-amd64 (4.9.189) to 4.9.0-12-amd64 
(4.9.209) the keepalived VIPs stop responding to ARP queries, causing 
the VIP to remain configured but unreachable on the VRRP master.