fix output dtype test in compute_types (#52731)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/52731
Test Plan: Imported from OSS
Reviewed By: mruberry
Differential Revision: D26630251
Pulled By: bhosmer
fbshipit-source-id: 5f61967c7e94882a3cc3c1b6beaa2b69d68b9656
