svnrdump: load_editor: Fix the docstrings in the header.
svnrdump: load_editor: Fix the docstrings in the header.

* subversion/svnrdump/load_editor.h
  (get_dumpstream_loader, drive_dumpstream_loader): Update docstrings.

Found by: danielsh

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion