Fix a bug in ra_serf's log handling which showed up when running 'svn log -vq' against a pre-1.5 server.  Instead of seeing something like:
Fix a bug in ra_serf's log handling which showed up when running 'svn
log -vq' against a pre-1.5 server.  Instead of seeing something like:

   ------------------------------------------------------------------------
   r1 | cmpilato | 2005-12-14 17:53:17 -0500 (Wed, 14 Dec 2005)
   Changed paths:
      A /trunk/www
      A /trunk/www/index.html
      M /src/data
   ------------------------------------------------------------------------

I was seeing:

   ------------------------------------------------------------------------
   r1 | cmpilato | 2005-12-14 17:53:17 -0500 (Wed, 14 Dec 2005)
   Changed paths:
      A /trunk/www
      A /trunk/www/index.html
      M This is my log message, which isn't supposed to be displaying
   ------------------------------------------------------------------------

* subversion/libsvn_ra_serf/log.c
  (end_log): Reset our temporary string's length even if we don't use
    its value.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@866906 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion