set the old SilcPacket to the packet thread's state context and move back
to the packet processor with silc_fsm_next and silc_fsm_continue_sync
(always synchronously, never async). This design may change later,
- but for now this is it. This also means that SILC_FSM_CALL must not
- be used in packet processors because it returns SILC_FSM_WAIT.
+ but for now this is it.
When to use FSM semaphore signalling?