Fix mistake in barry_as_FLUFL test (GH-31392)

Use assertEqual(), not assertTrue(lineno, 2)
(cherry picked from commit 5f1c205)

Co-authored-by: Patrick Reader <[email protected]>

Author: miss-islington

Lib/test/test_flufl.py

@@ -17,7 +17,7 @@ def test_barry_as_bdfl(self):
         self.assertIn('2 != 3', cm.exception.text)
         self.assertEqual(cm.exception.filename, '<FLUFL test>')
 
-        self.assertTrue(cm.exception.lineno, 2)
+        self.assertEqual(cm.exception.lineno, 2)
         # The old parser reports the end of the token and the new
         # parser reports the start of the token
         self.assertEqual(cm.exception.offset, 4 if support.use_old_parser() else 3)