Fix comments

Author: rednum

src/libcore/cmp.rs

@@ -246,7 +246,7 @@ impl Ordering {
         }
     }
 
-    /// Chain two orderings.
+    /// Chains two orderings.
     ///
     /// Returns `self` when it's not `Equal`. Otherwise returns `other`.
     /// # Examples
@@ -280,7 +280,7 @@ impl Ordering {
         }
     }
 
-    /// Chain the ordering with given function.
+    /// Chains the ordering with the given function.
     ///
     /// Returns `self` when it's not `Equal`. Otherwise calls `f` and returns
     /// the result.