mm/madvise.c: make madvise_behaviour_valid() return bool

This makes the madvise_bahaviour_valid() function return bool due to
this particular function always returning the value of either one or
zero as its return value.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/madvise.c b/mm/madvise.c
index 9113579..ce3a422 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -386,7 +386,7 @@
 	}
 }
 
-static int
+static bool
 madvise_behavior_valid(int behavior)
 {
 	switch (behavior) {
@@ -408,10 +408,10 @@
 #endif
 	case MADV_DONTDUMP:
 	case MADV_DODUMP:
-		return 1;
+		return true;
 
 	default:
-		return 0;
+		return false;
 	}
 }