Flight mode fixes

Agreed with Tony's comment, either we can shut down all radios or the operation should terminate with an error. Also, I do not understand why this test is not inside the "if (state != KILLSWITCH_STATE_NO_ADAPTER) {" statement.

Besides, it looks like urf_arbitrator_set_block() saves the state only when radio operation is successful. I do not actually understand what is saved-states file for. As discussed in launchpad, for me it makes sense only if we store there the desired state. We want to move the system to that state when we re-start urfkilld.