This patch removes a module_exit function that sgiioc4 should not have had.

It seems that the IDE layer doesn't support submodule unloading.  sgiioc4 was
the only driver in drivers/ide/pci that had an exit function.  After an
unload, the devices would stay around and the next attempt to reference would
crash...

Signed-off-by: Jeremy Higdon <jeremy@sgi.com>
Acked-by: "Bartlomiej Zolnierkiewicz" <bzolnier@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>