Don't use "with licenses;" for single licences

And don't use square brackets on such lines.

pkgs/development/libraries/librem/default.nix

@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
     homepage = "http://www.creytiv.com/rem.html";
     platforms = with stdenv.lib.platforms; linux;
     maintainers = with stdenv.lib.maintainers; [raskin];
-    license = with stdenv.lib.licenses; bsd3;
+    license = stdenv.lib.licenses.bsd3;
     inherit version;
     downloadPage = "http://www.creytiv.com/pub/";
     updateWalker = true;