Updates torch.floor_divide documentation to clarify it's actually torch.trunc_divide (or torch.rtz_divide) (#45411)
Summary:
Addresses https://github.com/pytorch/pytorch/issues/43874 for 1.7. 1.8 will need to take floor_divide through a proper deprecation process.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45411
Reviewed By: ngimel
Differential Revision: D23974997
Pulled By: mruberry
fbshipit-source-id: 16dd07e50a17ac76bfc93bd6b71d4ad72d909bf4
