This is preparatory to the introduction of a separate freeing API.

Reported-by: Amos Kong <akong@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Message-id: 1368454796-14989-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>