adjust async call stack querying API to guard against waiting in clearly-invalid cases (trying to wait for call stacks when running, for example); also eliminate logs

src/ctrl/ctrl_core.h

@@ -798,6 +798,7 @@ struct CTRL_State
   OS_Handle c2u_ring_cv;
   
   // rjf: ctrl thread state
+  U64 ctrl_thread_run_state;
   String8 ctrl_thread_log_path;
   OS_Handle ctrl_thread;
   Log *ctrl_thread_log;