document the usage of errCh

Kubernetes-commit: 5809b6a4282f7ce58e0d815d9326289a8ee7ddb6

pkg/server/filters/timeout.go

@@ -92,7 +92,8 @@ func (t *timeoutHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	errCh := make(chan interface{})
+	// resultCh is used as both errCh and stopCh
+	resultCh := make(chan interface{})
 	tw := newTimeoutWriter(w)
 	go func() {
 		defer func() {
@@ -103,12 +104,13 @@ func (t *timeoutHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				buf = buf[:runtime.Stack(buf, false)]
 				err = fmt.Sprintf("%v\n%s", err, buf)
 			}
-			errCh <- err
+			resultCh <- err
 		}()
 		t.handler.ServeHTTP(tw, r)
 	}()
 	select {
-	case err := <-errCh:
+	case err := <-resultCh:
+		// panic if error occurs; stop otherwise
 		if err != nil {
 			panic(err)
 		}