Fix compile break:

mod_mem_cache.c: In function `cleanup_cache_mem':
mod_mem_cache.c:251: too many arguments to function `cache_hash_first'
make[4]: *** [mod_mem_cache.slo] Error 1


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94933 13f79535-47bb-0310-9956-ffa450edef68