Merge pull request kubernetes#56069 from xiangpengzhao/change-kubeadm-validation

Automatic merge from submit-queue (batch tested with PRs 55839, 54495, 55884, 55983, 56069). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add condition "len(cfg.DiscoveryToken) != 0" to ValidateArgSelection.

**What this PR does / why we need it**:
as per kubernetes#54982 (comment)
>only when the conditions having len(cfg.DiscoveryToken) != 0 means "using token-based discovery" as is mentioned in the error message.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
ref: kubernetes#54982

**Special notes for your reviewer**:
/cc @kubernetes/sig-cluster-lifecycle-pr-reviews 

**Release note**:

```release-note
NONE
```

Author: Kubernetes Submit Queue

cmd/kubeadm/app/apis/kubeadm/validation/validation.go

@@ -140,7 +140,8 @@ func ValidateArgSelection(cfg *kubeadm.NodeConfiguration, fldPath *field.Path) f
 		allErrs = append(allErrs, field.Invalid(fldPath, "", "DiscoveryTokenCACertHashes cannot be used with DiscoveryFile"))
 	}
 
-	if len(cfg.DiscoveryFile) == 0 && len(cfg.DiscoveryTokenCACertHashes) == 0 && !cfg.DiscoveryTokenUnsafeSkipCAVerification {
+	if len(cfg.DiscoveryFile) == 0 && len(cfg.DiscoveryToken) != 0 &&
+		len(cfg.DiscoveryTokenCACertHashes) == 0 && !cfg.DiscoveryTokenUnsafeSkipCAVerification {
 		allErrs = append(allErrs, field.Invalid(fldPath, "", "using token-based discovery without DiscoveryTokenCACertHashes can be unsafe. set --discovery-token-unsafe-skip-ca-verification to continue"))
 	}