a code reduction function addition to cam_xpt

[mjacob at freebsd.org]

> 2006/12/5, mjacob at freebsd.org <mjacob at freebsd.org>:
>> 
>> 
>> Was there ever a consensus about this to the point of:
>> 
>> a) Yes, this is a nice thing to have
>> b) Should it be a define or a function?
>> 
>> I obviously  think yes for #a. I lean toward a function. Comments?
>
> a) yes
> b) define
>

A number of folks have spoken. On balance, the function is more 
readable. Thanks all.