Revert "Redefine scheduler to set learning rate using recursive formula" #14010 (#21463)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21463
ghimport-source-id: 1b0ea4a282b41388d5c6f6a5d18d37c14ae874ad
Differential Revision: D15747426
Pulled By: ezyang
fbshipit-source-id: 0708394f907b98a9f45bcfa26e5cc450fda8cf76
