CVE-2026-46014 KVM: SVM: Add missing save/restore handling of LBR MSRs

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Add missing save/restore handling of LBR MSRs MSRIA32DEBUGCTLMSR and LBR MSRs are currently not enumerated by KVMGETMSRINDEXLIST, and LBR MSRs cannot be set with KVMSETMSRS. So save/restore is completely broken. Fix it ...