Previously, if a PR was merged upstream and then a backport created from
it, the tool would incorrectly output the backport / upstream PRs in the
wrong order, implying that the PR that is actually upstream is the one
that is the backport, and vice versa. Fix it.
Previously, if a PR was merged upstream and then a backport created from it, the tool would incorrectly output the backport / upstream PRs in the wrong order, implying that the PR that is actually upstream is the one that is the backport, and vice versa. Fix it.