carp(4) code reduction

[Roy Marples <roy%marples.name@localhost>]

Hi List

With todays changes in -current I think it's possible to reduce the code
in carp_setroute. I don't use carp(4) and have little idea how it works,
but the patch looks right and mirrors an improvement made in other BSD.

What I don't know if it's correct, or the improvement relies on other
pieces as well.
The patch can be found here: http://www.netbsd.org/~roy/carp.diff

I won't apply it until I get some testing feedback or can try it myself.

Thanks

Roy