send_fd_length() did not calculate total_bytes_sent properly.

PR:		1366
Submitted by:	Ben Reser <breser@regnow.com>
Reviewed by:	Dean Gaudet, Dirk-Willem van Gulik, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79784 13f79535-47bb-0310-9956-ffa450edef68