Revert "fix RowwiseMoments vectorization issue on CPU (#81849)"
This reverts commit 4e9b969baa6ae36d41414a2b6138fcd694dcc2b6.
Reverted https://github.com/pytorch/pytorch/pull/81849 on behalf of https://github.com/malfet due to Revert as caused perf regression, see https://github.com/pytorch/benchmark/issues/1099
