p2p/discv5, p2p/testing: add missing Timer.Stop calls in tests (ethereum#20869)

Author: ucwong

p2p/discv5/sim_test.go

@@ -43,6 +43,7 @@ func TestSimRandomResolve(t *testing.T) {
 
 	// A new node joins every 10s.
 	launcher := time.NewTicker(10 * time.Second)
+	defer launcher.Stop()
 	go func() {
 		for range launcher.C {
 			net := sim.launchNode(false)
@@ -55,7 +56,6 @@ func TestSimRandomResolve(t *testing.T) {
 	}()
 
 	time.Sleep(3 * time.Hour)
-	launcher.Stop()
 	sim.shutdown()
 	sim.printStats()
 }
@@ -196,6 +196,7 @@ func randomResolves(t *testing.T, s *simulation, net *Network) {
 	}
 
 	timer := time.NewTimer(randtime())
+	defer timer.Stop()
 	for {
 		select {
 		case <-timer.C:

p2p/testing/protocolsession.go

@@ -242,6 +242,7 @@ func (s *ProtocolSession) testExchange(e Exchange) error {
 		t = 2000 * time.Millisecond
 	}
 	alarm := time.NewTimer(t)
+	defer alarm.Stop()
 	select {
 	case err := <-errc:
 		return err