cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter()
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 v5.15.86 by commit 22511eefa61db26e12c97dd7ada3071dbdfcb004, it was introduced in version v3.18 by commit f204e0b8cedd7da1dfcfd05ed6b7692737e24029. For more details please see the references link.