update checkpoint manager docstring (#866)

Summary:
Pull Request resolved: #866

fixes docstring reference to updated function name

Reviewed By: diego-urgell

Differential Revision: D59928251

fbshipit-source-id: 69d3f6a98c40b09333f021fd56ef7c21bf606701

Author: JKSenthil

torchtnt/utils/checkpoint.py

@@ -473,7 +473,7 @@ def should_save_checkpoint(self, checkpoint: CheckpointPath) -> bool:
     def append_checkpoint(self, ckpt: CheckpointPath) -> None:
         """
         This will update the internal state to keep track of the checkpoint. This function should only be called
-        when a checkpoint whose path was returned from `maybe_get_next_checkpoint_path` was successfully created.
+        when a checkpoint whose path was returned from `generate_checkpoint_path` was successfully created.
         If a previous checkpoint should be removed to honor `keep_last_n_checkpoint`, it will be deleted on rank 0.
 
         Args: