In libsvn_ra_serf: Following up on recent error handling behavior changes,
tweak the commit logic to report errors in a more sensible way. Also remove
an unneeded connection reset on a commit that requires a lock token.

* subversion/libsvn_ra_serf/commit.c
  (return_response_err): Rename to...
  (unexpected_status_error): ... this, to make it more clear that it just
    handles status codes. Server errors are already handled via the
    context loop, so there is no need to check those again.

  (checkout_node,
   proppatch_resource): Update caller.
  (delete_entry): Remove unnecessary reset. Simplify check. Use standard
    unexpected status response.
  (close_file): Update caller.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1553349 13f79535-47bb-0310-9956-ffa450edef68