Fixing Softmax bench. (#51898)
Summary:
Fixes and enables the microbenchmark for Softmax.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51898
Reviewed By: gmagogsfm
Differential Revision: D26333189
Pulled By: navahgar
fbshipit-source-id: be0934e413c4f6728593f896e53a0b31f1657e52
