merge this fix from 2.1-dev:

  mod_status: Report total CPU time accurately when using a threaded
  MPM.

PR:             23795
Submitted by:   Jeff Trawick
Reviewed by:    jim, ianh, nd


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@102050 13f79535-47bb-0310-9956-ffa450edef68