confstr() should return 0, not -1, on errors

[Joerg Sonnenberger]

On Sat, Dec 02, 2006 at 02:44:56PM -0800, Guy Harris wrote:
> According to
> 
>     http://www.opengroup.org/onlinepubs/009695399/functions/confstr.html
> 
> confstr() should return 0, not (size_t)-1, on errors.  The current 
> DragonFly BSD implementation returns -1 if sysctl() fails.

It should be noted that this is consistent with other BSDs. I don't have
a reference to POSIX.2 to verify the original specification.

Joerg