a code reduction function addition to cam_xpt

[mjacob at freebsd.org]

> mjacob at freebsd.org wrote:
>> 
>>> Erm, we make large use of variadic macros into the code :)
>> 
>> Yes. I think that if the code is never going to get backported to FBSD5 or 
>> earlier, it's probably fair enough to use, but for the aesthetics.
>
> You mean FreeBSD 4 or FreeBSD 5?  CAM is about to be pretty unportable back 
> to FreeBSD 4 for other reasons.

Ah, err, large chunks of it *do* go back.