xen/pcpu: fix possible memory leak in register_pcpu()
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 v4.19.267 by commit 6209a85079a035b5c2279b15b197531156b549fa, it was introduced in version v3.6 by commit f65c9bb3fb725551d3e405f4d092caf24929cebe. For more details please see the references link.