mm/mlock.c: change can_do_mlock return value type to boolean

Since can_do_mlock only return 1 or 0, so make it boolean.

No functional change.

[akpm@linux-foundation.org: update declaration in mm.h]
Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mlock.c b/mm/mlock.c
index 9197b67..e1e2b12 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -24,13 +24,13 @@
 
 #include "internal.h"
 
-int can_do_mlock(void)
+bool can_do_mlock(void)
 {
 	if (rlimit(RLIMIT_MEMLOCK) != 0)
-		return 1;
+		return true;
 	if (capable(CAP_IPC_LOCK))
-		return 1;
-	return 0;
+		return true;
+	return false;
 }
 EXPORT_SYMBOL(can_do_mlock);