clean up type_literal_test

TBR=leafp@google.com

Change-Id: Id8eebf4893103b187e981ccaf6c671ccdf659824
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107690
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Stephen Adams <sra@google.com>

Author: rakudrama

tests/language_2/type_literal_test.dart

@@ -99,11 +99,10 @@ void testType(Type type, Object expectedToStringValues) {
   String text = type.toString();
 
   // dart2js minified names should be tagged. We can still test types that don't
-  // contains minified names.
+  // contain minified names.
   if (text.contains('minified:')) return;
 
   if (expectedToStringValues is List) {
-    var s = type.toString();
     Expect.isTrue(expectedToStringValues.contains(text),
         'type `$type`.toString() should be one of: $expectedToStringValues.');
   } else {