macvlan: receive multicast with local address

macvlan: receive multicast with local address

When implementing VRRP v2 using macvlan several problems were
discovered.  VRRP is weird in that all routers participating
in a redundant group use the same virtual MAC address.
Macvlan is a natural driver to use for this but it doesn't
work.  The problem is that packets with a macvlan device's
source address are not received.

The problem is actually a regression that date back almost 2 years now.
The original problems started with:

commit 618e1b7482f7a8a4c6c6e8ccbe140e4c331df4e9
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Thu Nov 26 06:07:10 2009 +0000

    macvlan: implement bridge, VEPA and private mode

This patches restores the original 2.6.32 behavior. Allowing multicast
packets received with the VRRP source address to be received.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>