[PATCH] net: update the spider_net driver

- Prevent PCI posting problems by using synchronous register access
  in critical places

- Check return value from firmware device tree functions

- fix device cleanup

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>