add retry to update node label

fixing:
```
[FAILED] Unexpected error:
    <*errors.StatusError | 0xc000788780>:
    Operation cannot be fulfilled on nodes "worker-0": the object has been modified; please apply your changes to the latest version and try again
    {
        ErrStatus: {
            TypeMeta: {Kind: "", APIVersion: ""},
            ListMeta: {
                SelfLink: "",
                ResourceVersion: "",
                Continue: "",
                RemainingItemCount: nil,
            },
            Status: "Failure",
            Message: "Operation cannot be fulfilled on nodes \"worker-0\": the object has been modified; please apply your changes to the latest version and try again",
            Reason: "Conflict",
            Details: {Name: "worker-0", Group: "", Kind: "nodes", UID: "", Causes: nil, RetryAfterSeconds: 0},
            Code: 409,
        },
    }
```

Signed-off-by: Sebastian Sch <[email protected]>

Author: SchSeba

test/conformance/tests/test_sriov_operator.go

@@ -22,7 +22,8 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/fields"
 	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/utils/pointer"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/utils/ptr"
 	runtimeclient "sigs.k8s.io/controller-runtime/pkg/client"
 
 	sriovv1 "github.com/k8snetworkplumbingwg/sriov-network-operator/api/v1"
@@ -90,10 +91,10 @@ var _ = Describe("[sriov] operator", Ordered, func() {
 				Expect(err).ToNot(HaveOccurred())
 
 				Expect(len(selectedNodes)).To(BeNumerically(">", 0), "There must be at least one worker")
-				candidate := selectedNodes[0]
-				candidate.Labels["sriovenabled"] = "true"
-				_, err = clients.CoreV1Interface.Nodes().Update(context.Background(), &candidate, metav1.UpdateOptions{})
+				patch := []byte(`{"metadata":{"labels":{"sriovenabled":"true"}}}`)
+				candidate, err := clients.CoreV1Interface.Nodes().Patch(context.Background(), selectedNodes[0].Name, types.StrategicMergePatchType, patch, metav1.PatchOptions{})
 				Expect(err).ToNot(HaveOccurred())
+				selectedNodes[0] = *candidate
 
 				By("Setting the node selector for each daemon")
 				cfg := sriovv1.SriovOperatorConfig{}
@@ -468,7 +469,7 @@ var _ = Describe("[sriov] operator", Ordered, func() {
 					}
 
 					err = clients.Pods(namespaces.Test).Delete(context.Background(), podObj.Name, metav1.DeleteOptions{
-						GracePeriodSeconds: pointer.Int64Ptr(0)})
+						GracePeriodSeconds: ptr.To(int64(0))})
 					Expect(err).ToNot(HaveOccurred())
 
 					return found
@@ -953,8 +954,7 @@ var _ = Describe("[sriov] operator", Ordered, func() {
 				}, 2*time.Minute, 10*time.Second).Should(BeTrue(), "Error to detect Required Event")
 				By("Delete first pod and release all VFs")
 				err = clients.Pods(namespaces.Test).Delete(context.Background(), runningPodA.Name, metav1.DeleteOptions{
-					GracePeriodSeconds: pointer.Int64Ptr(0),
-				})
+					GracePeriodSeconds: ptr.To(int64(0))})
 				Expect(err).ToNot(HaveOccurred(), fmt.Sprintf("Error to delete pod %s", runningPodA.Name))
 				By("Checking that second pod is able to use released VF")
 				waitForPodRunning(runningPodB)