[pytorch][aten][cuda] fix LpNormFunctor (#70601)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70601
`&` has lower precedence than `==`, so `==` will be evaluated first. This behavior should not be intended. This patch fixes it.
Test Plan: 🧐 Carefully check the change.
Reviewed By: hyuen
Differential Revision: D33397964
fbshipit-source-id: e3ac5b04e4688dfbf9d8ac3e5c4aa72282bf6ee9
