Sample script argument is invalid.

rgName must be replaced with ResourceGroupName

Author: taoyama

articles/virtual-machines/windows/disk-encryption.md

@@ -170,7 +170,7 @@ $diskEncryptionSet=Get-AzDiskEncryptionSet -ResourceGroupName $ResourceGroupName
 
 $vm = Add-AzVMDataDisk -VM $vm -Name $diskName -CreateOption Empty -DiskSizeInGB $diskSizeinGiB -StorageAccountType $diskSKU -Lun $diskLUN -DiskEncryptionSetId $diskEncryptionSet.Id 
 
-Update-AzVM -ResourceGroupName $rgName -VM $vm
+Update-AzVM -ResourceGroupName $ResourceGroupName -VM $vm
 
 ```