Replace ExpectNoError(fmt.Errorf(..)) with funcs

There were framework.ExpectNoError(fmt.Errorf(..)) calls which just
raise an exception without actual value checks, they just raised the
specified error messages. These usages of framework.ExpectNoError()
seemed a little tricky, so this replaces them with corresponding check
functions for the readability.

test/e2e/network/ingress.go

@@ -182,9 +182,7 @@ var _ = SIGDescribe("Loadbalancing: L7", func() {
 				}
 				return true, nil
 			})
-			if pollErr != nil {
-				framework.ExpectNoError(fmt.Errorf("timed out waiting for ingress %s to get %s annotation", name, instanceGroupAnnotation))
-			}
+			framework.ExpectNoError(pollErr, "timed out waiting for ingress %s to get %s annotation", name, instanceGroupAnnotation)
 
 			// Verify that the ingress does not get other annotations like url-map, target-proxy, backends, etc.
 			// Note: All resources except the firewall rule have an annotation.

test/e2e/network/no_snat.go

@@ -141,9 +141,8 @@ var _ = SIGDescribe("NoSNAT [Feature:NoSNAT] [Slow]", func() {
 		ginkgo.By("creating a test pod on each Node")
 		nodes, err := nc.List(context.TODO(), metav1.ListOptions{})
 		framework.ExpectNoError(err)
-		if len(nodes.Items) == 0 {
-			framework.ExpectNoError(fmt.Errorf("no Nodes in the cluster"))
-		}
+		framework.ExpectNotEqual(len(nodes.Items), 0, "no Nodes in the cluster")
+
 		for _, node := range nodes.Items {
 			// find the Node's internal ip address to feed to the Pod
 			inIP, err := getIP(v1.NodeInternalIP, &node)