selftests/xsk: Avoid use-after-free on ctx
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 v5.15.75 by commit 37005a948677c3305fab6a3354e5c2945568d7c0, it was introduced in version v5.15.61 by commit 668fd740f8a6af04db3df38256e1626402dfd4b1. For more details please see the references link.