It's never used anywhere.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190520030839.6795-5-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>