sanlock: fix paxos acquire host_id check
    
    The host_id check should be skipped in the case where
    the local host_id was the previous paxos lease owner,
    but in a previous lockspace generation in which the
    paxos lease was not cleanly released.  Checking our
    own host_id does nothing and is a waste of time in
    this case.
    
    Signed-off-by: David Teigland <teigland@redhat.com>