build: remove warning 32 (unused variable) in tools.
build: remove warning 32 (unused variable) in tools.

(Patch by Adrien Nader!)

Among other files, myocamlbuild_config.ml is built in this directory.
This file defines many variables, most of which are not used and
therefore trigger this warning which is then turned into an error
through -warn-error A.
build: remove warning 32 (unused variable) in tools.

git-svn-id: e7e61699ce1738538ffebb75374fbea0924bc775@14169 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

yunxing/ocaml,eliberis/ocaml,yunxing/ocaml,chambart/camlp4,eliberis/ocaml,eliberis/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,eliberis/ocaml,msprotz/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,yallop/camlp4,eliberis/ocaml,hhugo/camlp4,msprotz/ocaml,gerdstolpmann/ocaml,msprotz/ocaml