Don't attempt to hold all of the response until we're done. We'll pass data on

when the zlib buffer becomes full and we need to reset the buffer anyway.

Also, tidy up a similar semantic when we see the EOS by returning an error
if ap_pass_brigade gets an error (we'd lose it otherwise).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@100730 13f79535-47bb-0310-9956-ffa450edef68