ACPI: processor: Rearrange and clean up acpi_processor_errata_piix4()

ACPI: processor: Rearrange and clean up acpi_processor_errata_piix4()

In acpi_processor_errata_piix4() it is not necessary to use three
struct pci_dev pointers.  One is sufficient, so use it everywhere and
drop the other two.

Additionally, define the auxiliary local variables value1 and value2
in the code block in which they are used.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2846888.mvXUDI8C0e@rafael.j.wysocki