Instead of using 2400 bytes in the stack for 150 MSR entries in
kvm_get_msrs() and kvm_put_msrs(), allocate a buffer once for
each VCPU.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>