Merge pull request #11640 from FRRouting/mergify/bp/stable/8.3/pr-11631

ldpd: Check if the thread is scheduled before calling for remained time (backport #11631)

Author: Jafaral

ldpd/adjacency.c

@@ -386,7 +386,9 @@ adj_to_ctl(struct adj *adj)
 	}
 	actl.holdtime = adj->holdtime;
 	actl.holdtime_remaining =
-	    thread_timer_remain_second(adj->inactivity_timer);
+		thread_is_scheduled(adj->inactivity_timer)
+			? thread_timer_remain_second(adj->inactivity_timer)
+			: 0;
 	actl.trans_addr = adj->trans_addr;
 	actl.ds_tlv = adj->ds_tlv;