Minor clean up for #616 test

Author: cowtowncoder

src/test/java/com/fasterxml/jackson/core/read/TrailingCommas616Test.java

@@ -5,30 +5,30 @@
 
 public class TrailingCommas616Test extends BaseTest
 {
-    final JsonFactory f = JsonFactory.builder()
+    private final JsonFactory JSON_F_ALLOW_MISSING = JsonFactory.builder()
             .enable(JsonReadFeature.ALLOW_MISSING_VALUES)
             .build();
 
     // [core#616]
     public void testRootLevelComma616() throws Exception
     {
-        _testRootLevel616(f, MODE_READER);
+        _testRootLevel616(MODE_READER);
     }
 
     public void testRootLevelComma616Bytes() throws Exception
     {
-        _testRootLevel616(f, MODE_INPUT_STREAM);
-        _testRootLevel616(f, MODE_INPUT_STREAM_THROTTLED);
+        _testRootLevel616(MODE_INPUT_STREAM);
+        _testRootLevel616(MODE_INPUT_STREAM_THROTTLED);
     }
 
     public void testRootLevelComma616DataInput() throws Exception
     {
-        _testRootLevel616(f, MODE_DATA_INPUT);
+        _testRootLevel616(MODE_DATA_INPUT);
     }
 
-    private void _testRootLevel616(JsonFactory f, int mode) throws Exception
+    private void _testRootLevel616(int mode) throws Exception
     {
-        JsonParser p = createParser(f, mode, ",");
+        JsonParser p = createParser(JSON_F_ALLOW_MISSING, mode, ",");
         try {
             p.nextToken();
             fail("Should not pass");