unbreak mypy torch/quantization (#49549)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49549
Somehow `mypy torch/quantization` got broken in the past couple of days:
https://gist.github.com/vkuzo/07af454246f0a68e6fa8929beeec7e0d
. I didn't see any relevant PRs other than
https://github.com/pytorch/pytorch/pull/47725, which doesn't seem
related. The error doesn't seem real, as the arguments to
`_cudnn_rnn_flatten_weight` seem correct. For now,
ignoring the failure so we have a clean `mypy` run on
`torch/quantization`.
Test Plan:
```
mypy torch/quantization
```
Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D25616972
fbshipit-source-id: 46c207fe1565ec949c0b1f57d6cd0c93f627e6bd
