Revert D23931987: Added optimizers based on multi tensor apply
Test Plan: revert-hammer
Differential Revision:
D23931987 (https://github.com/pytorch/pytorch/commit/2b21e7767e51d0a57297922598edb0fff9f0e722)
Original commit changeset: 582134ef2d40
fbshipit-source-id: ffd500aea55fda34155442fb15e2529cb9c00100
