[RELAY] bugfix type functor caching (#2113)

src/relay/ir/type_functor.cc

@@ -98,10 +98,10 @@ Type TypeMutator::VisitType_(const FuncTypeNode* op) {
   }
 
   Array<Type> new_args = MutateArray(op->arg_types);
-  changed = changed || new_args.same_as(op->arg_types);
+  changed = changed || !new_args.same_as(op->arg_types);
 
   Type new_ret_type = VisitType(op->ret_type);
-  changed = changed || new_ret_type.same_as(op->ret_type);
+  changed = changed || !new_ret_type.same_as(op->ret_type);
 
   if (!changed) return GetRef<Type>(op);
   return FuncTypeNode::make(new_args,