[Pytorch, sparsity] Bug fix to update requantization and zp parameters of input (#52797)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52797
Also sneaking in change to check for realloc failure for packed activation buffer
FB:
In dynamic quantization input's quantization scale and zero point can be
different on every iterations. Thus requantization scale needs to be
recomputed.
Earlier bug that calculated those only at op creation time results in wrong
results on subsequent runs.
This diff fixes that.
Test Plan:
FB:
buck test caffe2/torch/fb/model_optimization:sparsity_test
Reviewed By: z-a-f, jiatongzhou
Differential Revision: D26651968
fbshipit-source-id: e5b9acef03fc45f31c43d88a175f3a64f7dbf4bd
