proposal to stop using "backport: " in commit logs

[Ken Dreyer <kdreyer@redhat.com>]

A while ago this came up in #ceph-devel and I wanted to bring it to a
wider audience.

Should we stop the convention of adding the "backport: " tags in Git?

Loic brought up the point that this data is essentially immutable after
we merge it, and it's better to point at a Redmine tracker where we can
alter the "backport" field.

This makes it easier to adjust the "backport" data after the code's been
merged to master. It also makes it easier for whoever is corralling the
backport efforts, because the person only have one place to look
(Redmine) instead of two (Redmine + git commit logs).

For what it's worth I agree with Loic on this.

Any objections?

- Ken