SILC_FSM_CALL(function)

    Macro used to call asynchronous calls from state function.  If the
    call is not really asynchronous then this will cause the machine to
    directly proceed to next state.  If the call is truly asynchronous
    then this will set the machine to wait state.  The silc_fsm_next
    must be called before this macro, so that the next state is set.

    The state function returns in this macro.

    // Simple example
    silc_fsm_next(fsm, some_next_state);
    SILC_FSM_CALL(silc_some_async_call(server, some_callback, context));

    // More complex example
    silc_fsm_next(fsm, some_next_state);
    SILC_FSM_CALL((some_context->operation =
                   silc_some_async_call(server, some_callback, context)));