[O] export to latex without labels

[Salome \=\?iso-8859-1\?Q\?S\=F6dergran]

Hello experts,

I've been fiddling around for a while now with the following problem:

When I export something from org to latex I get plenty of \labels that I never 
refer to. I'd like to get rid of all those labels.
I found some code [1] that uses a hook that does not work in orgmode anymore. 
So I tried to adapt that code to the new orgmode way with 
org-export-filter-final-functions:

(defun ks/org-latex-remove-labels (backend info)
  "Remove labels generated by org-mode"
  (when (org-export-derived-backend-p backend 'latex)
  (let ((case-fold-search nil))
   (goto-char 1)
   (replace-regexp "\\\\label{sec-[0-9][^}]*}" "")
   )))

(eval-after-load 'ox-latex
  '(add-to-list 'org-export-filter-final-output-functions
            'ks/org-latex-remove-labels))


When I now try to export something from org to latex, I get the following error 
message:
 Wrong number of arguments: (lambda (backend) "Remove labels generated by 
org-mode" (if (org-export-derived-backend-p backend (quote latex)) (progn (let 
((case-fold-search nil)) (goto-char 1) (replace-regexp 
"\\\\label{sec-[0-9][^}]*}" ""))))), 3

I am just an emacs user, not a programmer, and I have no idea what's wrong and 
what I have to change to make it work. Can anyone give me a hint?
TIA, Salome


[1] 
http://stackoverflow.com/questions/18076328/org-mode-export-to-latex-suppress-generation-of-labels