sundance fixes

* all places where we assign ->addr get cpu_to_le32(pci_map_single(....)), so
we ought to convert back to host-endian before doing pci_unmap_single() et.al.
* poisoning addresses in netdev_close() should be done _after_ unmapping them,
not before it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>