xen/privcmd: fix error exit of privcmdioctldm_op()
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.15.64 by commit c2b7bae7c90051fd6a679d5dee00400d67ebbf4a, it was introduced in version v4.11 by commit ab520be8cd5d56867fc95cfbc34b90880faf1f9d. For more details please see the references link.