Fix logging in GitOutputOption.process_post_commit().

There is no "lod" variable at this point in the code.  Instead, report
the branch to which the commit is being written, which is always
trunk.

Reported by: Alex Kiernan <alexk@alexandalex.com>

git-svn-id: http://cvs2svn.tigris.org/svn/cvs2svn/trunk@5436 be7e6eca-30d4-0310-a8e5-ac0d63af7087