fix review finding

Author: sbueringer

bootstrap/kubeadm/api/v1beta1/kubeadmconfig_webhook.go

@@ -106,19 +106,17 @@ func (c *KubeadmConfigSpec) validateFiles(pathPrefix *field.Path) field.ErrorLis
 			if file.ContentFrom.Secret.Name == "" {
 				allErrs = append(
 					allErrs,
-					field.Invalid(
+					field.Required(
 						pathPrefix.Child("files").Index(i).Child("contentFrom", "secret", "name"),
-						file,
 						missingSecretNameMsg,
 					),
 				)
 			}
 			if file.ContentFrom.Secret.Key == "" {
 				allErrs = append(
 					allErrs,
-					field.Invalid(
+					field.Required(
 						pathPrefix.Child("files").Index(i).Child("contentFrom", "secret", "key"),
-						file,
 						missingSecretKeyMsg,
 					),
 				)