Fix the failure in TestEndpointSwitchResolvesViolation

Refer to a0bdfc4

Signed-off-by: Benjamin Wang <wachao@vmware.com>

tests/integration/clientv3/ordering_util_test.go

@@ -62,6 +62,7 @@ func TestEndpointSwitchResolvesViolation(t *testing.T) {
 	}
 
 	cli.SetEndpoints(eps...)
+	time.Sleep(1 * time.Second) // give enough time for the operation
 	orderingKv := ordering.NewKV(cli.KV, ordering.NewOrderViolationSwitchEndpointClosure(cli))
 	// set prevRev to the second member's revision of "foo" such that
 	// the revision is higher than the third member's revision of "foo"
@@ -72,9 +73,11 @@ func TestEndpointSwitchResolvesViolation(t *testing.T) {
 
 	t.Logf("Reconfigure client to speak only to the 'partitioned' member")
 	cli.SetEndpoints(clus.Members[2].GRPCURL())
+	time.Sleep(1 * time.Second) // give enough time for the operation
+	t.Log("Getting data from the partitioned member...")
 	_, err = orderingKv.Get(ctx, "foo", clientv3.WithSerializable())
 	if err != ordering.ErrNoGreaterRev {
-		t.Fatal("While speaking to partitioned leader, we should get ErrNoGreaterRev error")
+		t.Fatalf("While speaking to partitioned leader, we should get ErrNoGreaterRev error, %v", err)
 	}
 }