Bugfix: Initialize work_restart_notifier[1] to INVSOCK instead of -1 to be portable

miner.c

@@ -8165,7 +8165,7 @@ begin_bench:
 			thr->id = k;
 			thr->cgpu = cgpu;
 			thr->device_thread = j;
-			thr->work_restart_notifier[1] = -1;
+			thr->work_restart_notifier[1] = INVSOCK;
 			thr->_job_transition_in_progress = true;
 			timerclear(&thr->tv_morework);