add disk validation to creat provider

app/UI/VmCreate/Providers/VmCreateProvider.php

@@ -110,7 +110,7 @@ class VmCreateProvider extends BaseModelDataProvider implements ClientArea
         logModuleCall(
             'proxmoxCloud',
             __FUNCTION__,
-            $this->$formData,
+            $this->formData,
             'Debug',
             $this->vmTemplate->getSlaveHddsSize()
         );