DOC: Correct upsample doc to match interpolation (#38455)
Summary:
Fix https://github.com/pytorch/pytorch/issues/38334 and correct the docs of `torch.nn.functional.upsample`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38455
Differential Revision: D21583515
Pulled By: driazati
fbshipit-source-id: 6ac5a79ba489bdcdd3fab34e4eddb4864e20a29e
