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/mm/mmzone.c b/mm/mmzone.c
index 7d87ebb..52687fb 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -72,16 +72,16 @@
 }
 
 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
-int memmap_valid_within(unsigned long pfn,
+bool memmap_valid_within(unsigned long pfn,
 					struct page *page, struct zone *zone)
 {
 	if (page_to_pfn(page) != pfn)
-		return 0;
+		return false;
 
 	if (page_zone(page) != zone)
-		return 0;
+		return false;
 
-	return 1;
+	return true;
 }
 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */