return the actual number of bytes read when we're in "read a line" mode and it

looks like the line may never end.

This lets ap_getline determine whether there's excessive bytes or not,
depending on the size of its caller's buffers.  If the buffer can accomodate
more bytes, ap_getline will continue to read.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91713 13f79535-47bb-0310-9956-ffa450edef68