Fix a typo from earlier today. The filters accept apr_ssize_t's, so the

get_brigade code should also use apr_ssize_t.
Submitted by:	Greg Stein


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86572 13f79535-47bb-0310-9956-ffa450edef68