testfirmware: fix memory leak in testfirmware_init()
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 v5.10.163 by commit 0b5a89e8bce1ea43687742b4de8e216189ff94ac, it was introduced in version v4.14 by commit c92316bf8e94830a0225f2e904cbdbd173768419. For more details please see the references link.