Fix the test for cmp::Reverse

Author: mitsuhiko

src/libcore/cmp.rs

@@ -333,7 +333,7 @@ impl Ordering {
 /// use std::cmp::Reverse;
 ///
 /// let mut v = vec![1, 2, 3, 4, 5, 6];
-/// v.sort_by_key(|&num| (num >= 3, Reverse(num)));
+/// v.sort_by_key(|&num| (num > 3, Reverse(num)));
 /// assert_eq!(v, vec![3, 2, 1, 6, 5, 4]);
 /// ```
 #[derive(PartialEq, Eq, Debug)]