sanlock: Properly init io_timeout
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1292984
    
    Hold on to your hats, because this is gonna be wild.
    
    In bd3e16a3 I've tried to expose sanlock io_timeout. What I had
    not realized (because there is like no documentation for sanlock
    at all) was very unusual way their APIs work. Basically, what we
    do currently is:
    
        sanlock_add_lockspace_timeout(&ls, io_timeout);
    
    which adds a lockspace to sanlock daemon. One would expect that
    io_timeout sets the io_timeout for it. Nah! That's where you are
    completely off the tracks. It sets timeout for next lockspace you
    will probably add later. Therefore:
    
       sanlock_add_lockspace_timeout(&ls, io_timeout = 10);
       /* adds new lockspace with default io_timeout */
    
       sanlock_add_lockspace_timeout(&ls, io_timeout = 20);
       /* adds new lockspace with io_timeout = 10 */
    
       sanlock_add_lockspace_timeout(&ls, io_timeout = 40);
       /* adds new lockspace with io_timeout = 20 */
    
    And so on. You get the picture.
    Fortunately, we don't allow setting io_timeout per domain or per
    domain disk. So we just need to set the default used in the very
    first step and hope for the best (as all the io_timeout-s used
    later will have the same value).
    
    Signed-off-by: Michal Privoznik <mprivozn@redhat.com>