qemu:virtio-net: Check return size on the correct sg list (Alex Williamson)

When checking that the size of the control virtqueue return field
is sufficient, use the correct sg list.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6845 c046a42c-6fe2-441c-8c8c-71466251a162
