ftrace: Clean up hash direct_functions on register failures
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 v5.15.46 by commit cae2978d6907ef2c08b9b15f704e783f7c284713, it was introduced in version v5.5 by commit 763e34e74bb7d5c316015e2e39fcc8520bfd071c. For more details please see the references link.