mpm_winnt: Refactor the mpm_get_completion_context() function so that it

would return a proper apr_status_t instead of yielding the result via the
*timeout out variable.

This makes the calling side easier to follow by avoiding an additional
layer of if's.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1801147 13f79535-47bb-0310-9956-ffa450edef68