ACPI: Avoid NULL derefernce when hotplugging

Hi,

these are against 2.6.32, but patch fine against latest acpi release tree with a small offset.

Would be great to see them mainline soon.
The first is IMO a must for stable, eventually both should end up there.

Thanks,

Thomas

I guess I don't object to these.

I still hope that we can someday get rid of these external calls to acpi_bus_add(), acpi_bus_start(), etc., and instead have the Linux/ACPI code handle hotplug itself and call the driver .add() and .remove() methods like normal subsystems do.

But until we can do that, I guess we have to patch up the current code so it at least doesn't crash.

Bjorn