Use 'expected' rather than 'exp', as the latter shadows the exp()

function in the math.h header. Some compilers don't like that.

Submitted by: Blair Zajac <blair@orcaware.com>
Reviewed by: rbb@rkbloom.net


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@100280 13f79535-47bb-0310-9956-ffa450edef68