Fix weird doc bug (#1244)

* Update utils.py

* Update trl/trainer/utils.py

* Update trl/trainer/utils.py

trl/trainer/utils.py

@@ -367,7 +367,7 @@ class ConstantLengthDataset(IterableDataset):
                 Name of the field in the dataset that contains the text. Used only if `formatting_func` is `None`.
             formatting_func (`Callable`, **optional**):
                 Function that formats the text before tokenization. Usually it is recommended to have follows a certain
-                pattern such as `"### Question: {question}\n ### Answer: {answer}\n"`
+                pattern such as `"### Question: {question} ### Answer: {answer}"`
             infinite (`bool`, *optional*, defaults to `False`):
                 If True the iterator is reset after dataset reaches end else stops.
             seq_length (`int`, *optional*, defaults to `1024`):