Revert D26922420: [ONNX] fix export of embedding with padding_idx (#53053)
Test Plan: revert-hammer
Differential Revision:
D26922420 (https://github.com/pytorch/pytorch/commit/ee4ce8e9d9a439b9a87fcfa6abdcb0f7f3f62b11)
Original commit changeset: b8b867a96a13
fbshipit-source-id: 501392f419f2735658001c96f83d9754acd8e476
