kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb

kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb

Previously, we only called indirect_branch_prediction_barrier on the
logical CPU that freed a vmcb. This function should be called on all
logical CPUs that last loaded the vmcb in question.

Fixes: 15d45071523d ("KVM/x86: Add IBPB support")
Reported-by: Neel Natu <[email protected]>
Signed-off-by: Jim Mattson <[email protected]>
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
Cc: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>