Create the "pchild" pool which is created before child_init and destroyed

after child_exit.  This fixes a bug with reliable piped logs.

Reviewed by:	Jim Jagielski, Roy Fielding


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79590 13f79535-47bb-0310-9956-ffa450edef68