Fix inputs autoload with top-level follows

Previously, if the root node had follows, the autoloading code did not
work as it assumed the inputs of the root nodes were all strings and not
lists.

misc/lock2inputs.nix

@@ -43,4 +43,4 @@ let
 
   resolved = mapAttrs (_: resolveNode) nodes;
 in
-mapAttrs (_: v: resolved.${v}) rootNode.inputs
+mapAttrs (_: getInput) rootNode.inputs