lib.modules: compute disabled module list early

isDisabled gets the list of disabledModules ready when it's only given
two attributes, so when it's passed the third argument, it just has to
call `elem` on its precomputed list. This was being used in the graph
right below, but now in module filtering.

lib/modules.nix

@@ -564,7 +564,8 @@ let
         modulesPath:
         { disabled, modules }:
         let
-          keyFilter = filter (attrs: !isDisabled modulesPath disabled attrs);
+          isDisabledModule = isDisabled modulesPath disabled;
+          keyFilter = filter (attrs: !isDisabledModule attrs);
         in
         catAttrs "module" (genericClosure {
           startSet = keyFilter modules;