mISDN: fix possible use-after-free in HFC_cleanup()
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 v5.13.3 by commit ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda. For more details please see the references link.