Fix expansion of stride argument in avg_pool2d (#23961)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23961
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Differential Revision: D16695162
Pulled By: ezyang
fbshipit-source-id: 28eca6920bd1b4e72286b4ab859cf513dcd0db44
