dbr quant overhead [13/x]: cache results of get_module_hook_type (#68841)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68841
Caches the current module's hook type as an attribute on the module.
This requires the assumption that the current module's hook type
does not change during inference, which is an assumption we can
commit to.
Test Plan:
correctness
```
python test/test_quantization.py TestQuantizeDBR
```
performance
```
// MobileNetV2, 1x3x224x224, function profiling
// before
get_module_hook_type -> 2.58%
// after
get_module_hook_type -> 0.73%
```
Reviewed By: jerryzh168
Differential Revision: D32630881
Pulled By: vkuzo
fbshipit-source-id: 667f2667ef9c5514e5d82e4e7e4c02b8238edc65
