osd: do not apply_transaction in finish_recovery

osd: do not apply_transaction in finish_recovery

finish_recovery needs to set up a callback for when the current set of
changes commit to disk (to kickstart cleanup of strya replicas etc).  We
can't call apply_transaction this deep inside the call chain without
causing problems.  So, pass a list of completion contexts all the way down
so that we can set up the completion callback.