luasocket: fix eval

xref: cdbb0e2fb8fd8a5b5ae9c8f9faae72dd8b48bb4e

pkgs/top-level/lua-packages.nix

···
       );
     '';
 
-    meta = {
+    meta = with stdenv.lib; {
       homepage = "http://w3.impa.br/~diego/software/luasocket/";
       hydraPlatforms = with platforms; [darwin linux freebsd illumos];
       maintainers = with maintainers; [ mornfall ];