Objecter: rename cancel_op -> cancel_linger_op

This makes it possible to converse about op_cancel and cancel_linger_op
without getting too confused.

Signed-off-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
osd: name the objecter's messenger "ms_objecter" instead of "hbclient"

Bad copypasta on initial create?

Signed-off-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
osd: bind objecter messenger to cluster address

We don't want it binding to whatever willy-nilly, and as an OSD even
its "client" traffic should go on the cluster address.

Signed-off-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>