initctl: allow client_connect() to return error
initctl: allow client_connect() to return error

This lets any callers of client_connect() decide what to do wrt. error
recovery and fallback mechanisms.  E.g., reboot may want to check if
it's in sulogin mode, or fall back to sending signals to PID 1.

Signed-off-by: Joachim Wiberg <583c295fd7602c168ad814279bbc3894ba65f5d6@gmail.com>

troglobit/finit,troglobit/finit