MIPS: page.h: Provide more readable definition for PAGE_MASK.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/page.h

@@ -31,7 +31,7 @@
 #define PAGE_SHIFT	16
 #endif
 #define PAGE_SIZE	(_AC(1,UL) << PAGE_SHIFT)
-#define PAGE_MASK       (~((1 << PAGE_SHIFT) - 1))
+#define PAGE_MASK       (~(PAGE_SIZE - 1))
 
 #ifdef CONFIG_HUGETLB_PAGE
 #define HPAGE_SHIFT	(PAGE_SHIFT + PAGE_SHIFT - 3)