event: Avoid timer's mutex two successive locks/unlocks with unrelated (and
optional) work in between.

Also saves declaration/usage of pointer 'ep' by reusing available 'te' instead,
and removes duplicated 'te' declaration in a local block.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1604466 13f79535-47bb-0310-9956-ffa450edef68