fix view call on discontiguous tensor in to_sparse_backward (#31223)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/30820
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31223
Differential Revision: D19044172
Pulled By: ngimel
fbshipit-source-id: ac9fa71197d4f6c5b90a26e8d23360250745a2e2
