alpha: nautilus - fix hang on boot

Recently introduced generic pci_common_swizzle() relies on bus->self
being NULL for the root PCI bus. But on nautilus bus->self points to
the host bridge device, which is necessary as we do a root bus sizing
on this system. As a result, pci_common_swizzle() loops infinitely.
This worked until 2.6.29-rc1 because the alpha-specific swizzle routine
checked for bus->parent == NULL (instead of bus->self).

Fixed by clearing bus->self after bus sizing is done.

Signed-off-by: Ivan Kokshaysky <[e-mail]>
Cc: Richard Henderson <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/alpha/kernel/sys_nautilus.c

···
 		IRONGATE0->pci_mem = pci_mem;
 
 	pci_bus_assign_resources(bus);
+
+	/* pci_common_swizzle() relies on bus->self being NULL
+	   for the root bus, so just clear it. */
+	bus->self = NULL;
 	pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq);
 }