The buffer content might be read out more than once, currently
we just repeatedly read the first data block, buffer offset is
missing.

Cc: qemu-stable@nongnu.org
Signed-off-by: Amos Kong <akong@redhat.com>
Message-id: 1385023371-8198-3-git-send-email-akong@redhat.com
Signed-off-by: Anthony Liguori <aliguori@amazon.com>