Remove unused th_scalar_type (#18390)
Summary:
th_scalar_type seems to be unused anywhere so can be removed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18390
Reviewed By: ezyang
Differential Revision: D14591374
Pulled By: izdeby
fbshipit-source-id: 2113aa81229cdfdfb8dc5c951ea6dea3725b8582
