We should only be doing one socket read under any circumstances

(blocking or not).

apr_brigade_partition would do reading multiple times and that's
not really what we want (so I think).

This may speed up POST requests that were waiting for all of the
data to arrive before returning anything in blocking mode.

Reviewed by:	Greg Stein, Ryan Bloom


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91322 13f79535-47bb-0310-9956-ffa450edef68