fixed a bug resulting in occasional starter crashes
diff --git a/aos/linux_code/starter/starter.cc b/aos/linux_code/starter/starter.cc
index f0994b9..616bbdb 100644
--- a/aos/linux_code/starter/starter.cc
+++ b/aos/linux_code/starter/starter.cc
@@ -138,7 +138,7 @@
   void RemoveWatchFromMap() {
     int watch = watch_to_remove_;
     if (watch == -1) {
-      CHECK_NE(watch, -1);
+      CHECK_NE(watch_, -1);
       watch = watch_;
     }
     if (watchers[watch] != this) {