fixes #25641, error message when type arguments do not match

pkg/analyzer/lib/src/generated/element_resolver.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.generated.element_resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 1501 matching lines @@
    */
   DartType _instantiateGenericMethod(
       DartType invokeType, TypeArgumentList typeArguments, AstNode node) {
     // TODO(jmesserly): support generic "call" methods on InterfaceType.
     if (invokeType is FunctionType) {
       FunctionType type = invokeType;
       List<TypeParameterElement> parameters = type.typeFormals;
 
       NodeList<TypeName> arguments = typeArguments?.arguments;
       if (arguments != null && arguments.length != parameters.length) {
-        // Wrong number of type arguments. Ignore them
-        arguments = null;
         _resolver.reportErrorForNode(
             StaticTypeWarningCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS,
             node,
             [type, parameters.length, arguments?.length ?? 0]);
+
+        // Wrong number of type arguments. Ignore them.
+        arguments = null;
       }
       if (parameters.isNotEmpty) {
         if (arguments == null) {
           invokeType = _resolver.typeSystem.instantiateToBounds(type);
         } else {
           invokeType = type.instantiate(arguments.map((n) => n.type).toList());
         }
       }
     }
     return invokeType;
@@ skipping 1055 matching lines @@
 
   @override
   Element get staticElement => null;
 
   @override
   accept(AstVisitor visitor) => null;
 
   @override
   void visitChildren(AstVisitor visitor) {}
 }