replace non-blocking send, receive syntax with select

R=golang-dev, nigeltao, niemeyer, r
CC=golang-dev
https://golang.org/cl/4079053
diff --git a/src/pkg/time/sleep_test.go b/src/pkg/time/sleep_test.go
index 4007db5..8bf599c 100644
--- a/src/pkg/time/sleep_test.go
+++ b/src/pkg/time/sleep_test.go
@@ -120,10 +120,12 @@
 		t.Fatalf("failed to stop event 1")
 	}
 	<-c2
-	_, ok0 := <-t0.C
-	_, ok1 := <-c1
-	if ok0 || ok1 {
-		t.Fatalf("events were not stopped")
+	select {
+	case <-t0.C:
+		t.Fatalf("event 0 was not stopped")
+	case <-c1:
+		t.Fatalf("event 1 was not stopped")
+	default:
 	}
 	if t1.Stop() {
 		t.Fatalf("Stop returned true twice")