Revert D20006312: Revert D19975410: Update documentation on why _cudnn_init_dropout_state looks the way it is.
Test Plan: revert-hammer
Differential Revision:
D20006312
Original commit changeset: 4d4cc8ae78ad
fbshipit-source-id: 4bd4b9d1331dc97f5b83e0df491be5fd0a11214a
