Unnecessary sleep in network.subr: ipv6_up()

[Dennis Koegel]

Cheers,

problem: Having a *lot* of IPv6 interfaces (Vlan interfaces in this case)
causes a huge and annoying delay time at system boot in 9.0R.

ipv6_up() in network.subr does this:

+	# wait for DAD
+	sleep `${SYSCTL_N} net.inet6.ip6.dad_count`
+	sleep 1

This happens for each and every interface, at a minimum (and default) of
two seconds per interface.

It seems the behaviour was introduced with r197139. Before this merge,
/etc/rc.d/network_ipv6 did the same sleeps, but only once for the whole
network startup.

I don't see why this should happen per interface, so I suggest the extra
sleeps are limited to "once per network startup" once again (or maybe
removed?).

- D.