Revert D22780307: Fix illegal memory acess issue for CUDA versionn of SplitByLengths operator.
Test Plan: revert-hammer
Differential Revision:
D22780307 (https://github.com/pytorch/pytorch/commit/76905527fe4d1caab195b280f0ec897c6c4251a6)
Original commit changeset: c5ca60ae16b2
fbshipit-source-id: f3c99eec5f05121e2bed606fe2ba84a0be0cdf16
