quantizer.cpp: fix cuda memory pinning (#41139)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41139
Fixes the test case in https://github.com/pytorch/pytorch/issues/41115
by using PyTorch's CUDA allocator instead of the old Caffe2 one.
Test Plan:
run the test case from the issue:
https://gist.github.com/vkuzo/6d013aa1645cb986d0d4464a931c779b
let's run CI and see what it uncovers
Imported from OSS
Reviewed By: malfet
Differential Revision: D22438787
fbshipit-source-id: 0853b0115d198a99c43e6176aef34ea951bf5c2e
