[PATCH] x86-64: Fix partial page check to ensure unusable memory is not being marked usable.

Fix partial page check in e820_register_active_regions to ensure
partial pages are
not being marked as active in the memory pool.

Signed-off-by: Aaron Durbin <adurbin@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>