don't have to release lock when using CVs, it does that for you

kern/synchprobs/traffic_synch.c

@@ -220,8 +220,7 @@ void intersection_before_entry(Direction origin, Direction destination)
       else
       {
         new->old = 1; // make new "old", since now it has already waited once
-        lock_release(globlock);
-        
+
         // create cv for temp if it doesn't have one yet
         if(!(temp->cv))
         {