ax25: fix UAF bug in ax25sendcontrol()
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 v5.4.190 by commit eaa7eb23fa76db45f7da1b6192518705863d0ebe, it was introduced in version v5.4.190 by commit 9e1e088a57c23251f1cfe9601bbd90ade2ea73b9. For more details please see the references link.