std/var: Return real results for complex input (#58066)
Summary:
Fixes gh-56627
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58066
Reviewed By: ngimel
Differential Revision: D28372987
Pulled By: mruberry
fbshipit-source-id: c34d55f1a48047ceefa298ef2f4f33ad7dd1e577
