Update: sysutils/stress

[Rui Reis]

Here's an update for stress 0.18.8, works fine for me on i386, amd64 and
sparc64.

http://www.openbsd-pt.com/ports/stress-0.18.8.diff

Changelog available here: 
http://weather.ou.edu/~apw/projects/stress/ChangeLog

Test and comment.
Rui Reis