Fix build: missing error marker in neg test

Author: smarter

tests/neg/namedTypeParams.scala

@@ -11,6 +11,6 @@ object Test {
 
   def f[X, Y](x: X, y: Y): Int = ???
 
-  f[X = Int, String](1, "") // error
+  f[X = Int, String](1, "") // error // error
   f[X = Int][X = Int][Y = String](1, "") // error
 }