xen/console: harden hvc_xen against event channel storms
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 v4.9.294 by commit 728389c21176b2095fa58e858d5ef1d2f2aac429. For more details please see the references link.