CARP missing sysctl options

[elekktretterr at exemail.com.au]

Hi there,
While testing CARP in HEAD, trying to resolve my previous CARP related
kernel panic,
I noticed that we dont have any sysctl tunables for CARP in net.inet.carp,
even though they are mentioned in the CARP man page. I consider
net.inet.carp.preempt to be an absolutely necessary option for it to be
any useful to me.

Can we please add it?
Thanks,

Petr