Revert "Merge remote branch 'upstream/master'"

This reverts commit 311ce2bd9b78a6746f9cec7a7bcf1a53654a1c46, reversing
changes made to 7828cf43526c262b8b1ce1dbba49bb24280a6a11.

IMPORTANT: this revert must itself be reverted to re-merge upstream/master
           % git revert <this change>

           https://www.kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.txt