media: cx88: Fix a null-ptr-deref bug in buffer_prepare()
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 v5.15.75 by commit 6f21976095c1e92454ab030976f95f40d652351b. For more details please see the references link.