Rollup merge of rust-lang#59831 - ehuss:ordering-docs, r=kennytm

Remove strange formatting in `Ordering` docs.

I can't really fathom what the intent of the brackets is. The [original PR](rust-lang#12956) doesn't give any hints. I think it seems fine without them.

src/libcore/cmp.rs

@@ -286,13 +286,13 @@ pub struct AssertParamIsEq<T: Eq + ?Sized> { _field: ::marker::PhantomData<T> }
 #[derive(Clone, Copy, PartialEq, Debug, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub enum Ordering {
-    /// An ordering where a compared value is less [than another].
+    /// An ordering where a compared value is less than another.
     #[stable(feature = "rust1", since = "1.0.0")]
     Less = -1,
-    /// An ordering where a compared value is equal [to another].
+    /// An ordering where a compared value is equal to another.
     #[stable(feature = "rust1", since = "1.0.0")]
     Equal = 0,
-    /// An ordering where a compared value is greater [than another].
+    /// An ordering where a compared value is greater than another.
     #[stable(feature = "rust1", since = "1.0.0")]
     Greater = 1,
 }