mm/mmzone.c: memmap_valid_within() can be boolean

Make memmap_valid_within return bool due to this particular function
only using either one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 12c98df..3b6fb71 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1200,13 +1200,13 @@
  * the zone and PFN linkages are still valid. This is expensive, but walkers
  * of the full memmap are extremely rare.
  */
-int memmap_valid_within(unsigned long pfn,
+bool memmap_valid_within(unsigned long pfn,
 					struct page *page, struct zone *zone);
 #else
-static inline int memmap_valid_within(unsigned long pfn,
+static inline bool memmap_valid_within(unsigned long pfn,
 					struct page *page, struct zone *zone)
 {
-	return 1;
+	return true;
 }
 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */