xen/xenbus: don't let xenbusgrantring() remove grants in error case
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 v4.9.306 by commit 8f80d12f6946a6fe7c64bfc204c062a57f83c7f8. For more details please see the references link.