Update device type issues present in _generate_answers method.

flash/text/question_answering/model.py

@@ -135,10 +135,10 @@ def _generate_answers(self, pred_start_logits, pred_end_logits, examples):
                 }
 
             # Go through all possibilities for the `n_best_size` greater start and end logits.
-            start_indexes: List[int] = np.argsort(start_logits.clone().detach().numpy())[
+            start_indexes: List[int] = np.argsort(start_logits.clone().detach().cpu().numpy())[
                 -1 : -self.n_best_size - 1 : -1
             ].tolist()
-            end_indexes: List[int] = np.argsort(end_logits.clone().detach().numpy())[
+            end_indexes: List[int] = np.argsort(end_logits.clone().detach().cpu().numpy())[
                 -1 : -self.n_best_size - 1 : -1
             ].tolist()