[caffe2] Fix the timeout (stuck) issues of dedup SparseAdagrad C2 kernel
Summary:
Backout D22800959 (https://github.com/pytorch/pytorch/commit/f30ac66e7970dae2833e390bc623ea29141c8ff9). This one is causing the timeout (machine stuck) issues for dedup kernels. Reverting it make the unit test pass. Still need to investigate why this is the culprit...
Original commit changeset: 641d52a51070
Test Plan:
```
buck test mode/dev-nosan //caffe2/caffe2/fb/net_transforms/tests:fuse_sparse_ops_test -- 'test_fuse_sparse_adagrad_with_sparse_lengths_sum_gradient \(caffe2\.caffe2\.fb\.net_transforms\.tests\.fuse_sparse_ops_test\.TestFuseSparseOps\)' --print-passing-details
```
Reviewed By: jspark1105
Differential Revision: D23008389
fbshipit-source-id: 4f1b9a41c78eaa5541d57b9d8aa12401e1d495f2
