[PATCH] x86_64: Do more checking in the SRAT header code

 - Check if the processor/memory affinity entries are long enough
   according to the ACPI 3.0 spec.
 - Ignore memory affinity entries that define a zero length region.

All based on BIOS issues found in the field @)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>