Revert D28859795: [nnc] Enable CPU fusion inside Facebook, take 4
Test Plan: revert-hammer
Differential Revision:
D28859795 (https://github.com/pytorch/pytorch/commit/6baa66ece91be9a8dcee40cc37f78a16ca1fd16e)
Original commit changeset: 826801db24e8
fbshipit-source-id: c85a0fc7e88c95af939d5c0f50c0c8878e1174d3
