Revert "Vectorize non-persistent Softmax kernels (#36485)" (#38534)
Summary:
This reverts commit c879c6fb98ec38197c86c703e1011c8b94f14c59.
(it produces incorrect results)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38534
Reviewed By: soumith
Differential Revision: D21589251
Pulled By: ngimel
fbshipit-source-id: 66d5324848d0245d15b7ef5f1fe4302ed0992b56
