google-chrome: Fix fetching upstream binary

Commit aa097946d226aabbe77623800a825b3ee74180c4 only fixed evaluation.

Ssince 37dbd62 however, the fetchurl call is already implied so just
changing the path will still result in fetchurl (fetchurl ...), so let's
drop the outer fetchurl.

Signed-off-by: aszlig <[e-mail]>
Cc: @msteen, @benley

pkgs/applications/networking/browsers/google-chrome/default.nix

···
 
   name = "google-chrome-${version}";
 
-  src = fetchurl binary;
+  src = binary;
 
   buildInputs = [ env patchelf ];