x86/kvm: fix FASTOP_SIZE when return thunks are enabled
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 v5.15.57 by commit 198685e58b134679e6079d872396f4352780282f, it was introduced in version v5.15.57 by commit 1d61a2988612ac0632134454d5407c63ae0b9d42. For more details please see the references link.