dag: cleanup some code that had no effect anymore

dag/walk.go

@@ -173,13 +173,9 @@ func (w *Walker) Update(g *Graph) {
 		info := &walkerVertex{
 			DoneCh:   make(chan struct{}),
 			CancelCh: make(chan struct{}),
-			DepsCh:   make(chan bool, 1),
 			deps:     make(map[Vertex]chan struct{}),
 		}
 
-		// Pass dependencies immediately assuming we have no edges
-		info.DepsCh <- true
-
 		// Add it to the map and kick off the walk
 		w.vertexMap[v] = info
 	}