Merge r1405856 from trunk:

* fd is no member of disk_cache_object_t. Instead it is a member of
  disk_cache_file_t. Close all fd's (fd, tempfd) for all cache elements
  (hdrs, data, vary) if they are present.

Submitted by: rpluem
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1420827 13f79535-47bb-0310-9956-ffa450edef68