The SRU request for jessie is in #887857. I don't think there is a way to get a fix into jessie-backports, so I think we will need to remove openafs-modules-source and openafs-modules-dkms from jessie-backports and pull the version from buster into jessie-backports-sloppy (which will be a trip through NEW and require a DD sponsor, since I'm only a DM).
I'm still looking at wheezy. -Ben