kmemcheck: don't track page tables

As these are allocated using the page allocator, we need to pass
__GFP_NOTRACK before we add page allocator support to kmemcheck.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 6ce9518..3cfe9ce 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -470,7 +470,7 @@
 
 	if (!debug_pagealloc)
 		spin_unlock(&cpa_lock);
-	base = alloc_pages(GFP_KERNEL, 0);
+	base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0);
 	if (!debug_pagealloc)
 		spin_lock(&cpa_lock);
 	if (!base)