[numpy] `torch.erf{c}` : promote integer inputs to float (#48472)
Summary:
Reference: https://github.com/pytorch/pytorch/issues/42515
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48472
Reviewed By: ngimel
Differential Revision: D25192324
Pulled By: mruberry
fbshipit-source-id: 6ef2fec8a27425f9c4c917fc3ae25ac1e1f5f454