[mbart] Fix fp16 testing logic (#4949)

tests/test_modeling_bart.py

@@ -249,7 +249,7 @@ class MBartIntegrationTests(unittest.TestCase):
         with torch.no_grad():
             logits, *other_stuff = model(**net_input)
 
-        expected_slice = torch.tensor([9.0078, 10.1113, 14.4787], device=torch_device)
+        expected_slice = torch.tensor([9.0078, 10.1113, 14.4787], device=torch_device, dtype=model.dtype)
         result_slice = logits[0][0][:3]
         self.assertTrue(torch.allclose(expected_slice, result_slice, atol=TOLERANCE))
 
@@ -293,9 +293,6 @@ class MBartIntegrationTests(unittest.TestCase):
         expected_shape = (*summary.shape, config.vocab_size)
         self.assertEqual(logits.shape, expected_shape)
 
-
-@require_torch
-class MBartTokenizerTests(MBartIntegrationTests):
     def test_enro_tokenizer_prepare_translation_batch(self):
         batch = self.tokenizer.prepare_translation_batch(
             self.src_text, tgt_texts=self.tgt_text, max_length=len(self.expected_src_tokens),