xen/netfront: react properly to failing gnttabendforeignaccessref()
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 v4.19.234 by commit c307029d811e03546d18d0e512fe295b3103b8e5. For more details please see the references link.