Revert "Use visitor"

This reverts commit e470075.

See: CosmWasm#2309

packages/schema/src/schema_for.rs

@@ -24,19 +24,10 @@ macro_rules! schema_for {
         )
         .into_root_schema_for::<$type>();
 
-        struct Visitor;
-        impl $crate::schemars::visit::Visitor for Visitor {
-            fn visit_schema_object(&mut self, schema: &mut $crate::schemars::schema::SchemaObject) {
-                $crate::schemars::visit::visit_schema_object(self, schema);
-
-                if let Some(ref mut validation) = schema.object {
-                    validation.additional_properties = Some(Box::new(false.into()));
-                }
-            }
+        if let Some(ref mut validation) = schema.schema.object {
+            validation.additional_properties = Some(Box::new(false.into()));
         }
 
-        $crate::schemars::visit::visit_root_schema(&mut Visitor, &mut schema);
-
         schema
     }};
     ($_:expr) => {