tracing: Fix memory leak in testgensynthcmd() and testemptysynthevent()
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 v5.10.156 by commit 65ba7e7c241122ef0a9e61d1920f2ae9689aa796, it was introduced in version v5.6 by commit 9fe41efaca08416657efa8731c0d47ccb6a3f3eb. For more details please see the references link.