Satisfy Rubocop

Fixes offense:

```
actionpack/test/journey/router_test.rb:493:37: C: Style/HashSyntax: Use the new Ruby 1.9 hash syntax.
            options = options.merge(:_recall => recall)
                                    ^^^^^^^^^^^
```

actionpack/test/journey/router_test.rb

@@ -490,7 +490,7 @@ def test_eager_load_without_routes
       private
         def _generate(route_name, options, recall)
           if recall
-            options = options.merge(:_recall => recall)
+            options = options.merge(_recall: recall)
           end
           path = @route_set.path_for(options, route_name)
           uri = URI.parse path