osd: always mark down old hb peers; send map update via cluster link
osd: always mark down old hb peers; send map update via cluster link

If we don't mark down the hb link immediately, we'll forget about it
because it won't be in the from or to set anymore, and if it does go down
later we'll end up with garbage in the logs.

Instead, always mark it down.  Since we want to share our map with old
peers that are still up, do that via the cluster link instead, which is
reliably marked down if/when the peer goes down.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph