The pthread_mutex_ functions do not set errno, they return an errno

value.  I'm committing this because it was posted on nov 20, and I'm
tired of it sitting in my tree uncommitted.

Submitted by:	Igor Tatarinov <tatarino@prairie.NoDak.edu>
Reviewed by:	Dean Gaudet


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79683 13f79535-47bb-0310-9956-ffa450edef68