x86: rename PTE_MASK to PTE_PFN_MASK

Rusty, in his peevish way, complained that macros defining constants
should have a name which somewhat accurately reflects the actual
purpose of the constant.

Aside from the fact that PTE_MASK gives no clue as to what's actually
being masked, and is misleadingly similar to the functionally entirely
different PMD_MASK, PUD_MASK and PGD_MASK, I don't really see what the
problem is.

But if this patch silences the incessent noise, then it will have
achieved its goal (TODO: write test-case).

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index a44d56e..0db6912 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -343,8 +343,8 @@
 static pteval_t pte_mfn_to_pfn(pteval_t val)
 {
 	if (val & _PAGE_PRESENT) {
-		unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT;
-		pteval_t flags = val & ~PTE_MASK;
+		unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+		pteval_t flags = val & ~PTE_PFN_MASK;
 		val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
 	}
 
@@ -354,8 +354,8 @@
 static pteval_t pte_pfn_to_mfn(pteval_t val)
 {
 	if (val & _PAGE_PRESENT) {
-		unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT;
-		pteval_t flags = val & ~PTE_MASK;
+		unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+		pteval_t flags = val & ~PTE_PFN_MASK;
 		val = ((pteval_t)pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
 	}