tracing: Fix wild-memory-access in registersynthevent()
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 v5.15.80 by commit 6517b97134f724d12f673f9fb4f456d75c7a905f, it was introduced in version v4.17 by commit 4b147936fa509650beaf638b331573c23ba4d609. For more details please see the references link.