Add error output to integration test TestGoBGPLifecycle

The testGoBGPLifecycle gets failed occasionally, and it is not easy
to reproduce the failure manually. Adding some error output
to which the error occurs may help to resolve the issue.

Signed-off-by: Hongliang Liu <lhongliang@vmware.com>

test/integration/agent/gobgp_test.go

@@ -122,10 +122,12 @@ func TestGoBGPLifecycle(t *testing.T) {
 		peerKeys := sets.New[string]()
 		peers, err := server.GetPeers(ctx)
 		if err != nil {
+			t.Logf("Failed to get peers from server: %v", err)
 			return nil
 		}
 		for _, peer := range peers {
 			if peer.SessionState != bgp.SessionEstablished {
+				t.Logf("Skip peer %s with session state %s", peer.Address, peer.SessionState)
 				continue
 			}
 			peerKeys.Insert(fmt.Sprintf("%s-%d", peer.Address, peer.ASN))
@@ -194,6 +196,7 @@ func TestGoBGPLifecycle(t *testing.T) {
 	getReceivedRoutesFn := func(server bgp.Interface, peerAddress string) []bgp.Route {
 		routes, err := server.GetRoutes(ctx, bgp.RouteReceived, peerAddress)
 		if err != nil {
+			t.Logf("Failed to get routes from server: %v", err)
 			return nil
 		}
 		return routes