dbr quant: remove unnecessary outputs hook (#68838)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68838
Removes an unnecessary outputs hook on the top level
module. The same hook is already called inside the regular
hook flow.
Test Plan:
```
python test/test_quantization.py TestQuantizeDBR
```
Reviewed By: soulitzer
Differential Revision: D32630882
Pulled By: vkuzo
fbshipit-source-id: aa5f1b1cb866051013195d7311949333b08df4de
