Pull up following revision(s) (requested by bouyer in ticket #1067):
	sys/dist/ipf/netinet/ip_fil_netbsd.c	1.9 via patch
	sys/net/if_ethersubr.c			1.197 via patch
	sys/net/if_loop.c			1.77 via patch
	sys/net/if_vlan.c			1.70 via patch
	sys/netinet/if_arp.c			1.158
	sys/netinet/ip_carp.c			1.54 via patch
	sys/netinet6/ip6_flow.c			1.23 via patch
	sys/netinet6/nd6.c			1.150 via patch
	sys/rump/librump/rumpkern/klock.c	1.4

Make sure *(if_output)() is called with KERNEL_LOCK held to avoid mbuf leak.
See http://mail-index.netbsd.org/tech-net/2014/04/09/msg004511.html
for details. For netinet6, the problem report, fix and test were done
by njoly@ on current-users@
Ticket 1067.