watcher: fix wrong comparison

cmd/watcher/validator.go

@@ -15,7 +15,7 @@ type validator struct {
 }
 
 func (v *validator) stop() {
-	if v.ticker == nil || v.stop == nil {
+	if v.ticker == nil || v.done == nil {
 		v.ticker.Stop()
 		v.done <- true
 	}