Remove reference to generic types within XML comment.

Visual Studio is happy with it, but Mono isn't :(
diff --git a/csharp/src/Google.Protobuf/CodedOutputStream.cs b/csharp/src/Google.Protobuf/CodedOutputStream.cs
index 7f41cb7..d6355f0 100644
--- a/csharp/src/Google.Protobuf/CodedOutputStream.cs
+++ b/csharp/src/Google.Protobuf/CodedOutputStream.cs
@@ -51,8 +51,8 @@
     /// this class should just call one of the <c>WriteTag</c> overloads before each value.

     /// </para>

     /// <para>

-    /// Repeated fields and map fields are not handled by this class; use <see cref="RepeatedField{T}"/>

-    /// and <see cref="MapField{TKey, TValue}"/> to serialize such fields.

+    /// Repeated fields and map fields are not handled by this class; use <c>RepeatedField&lt;T&gt;</c>

+    /// and <c>MapField&lt;TKey, TValue&gt;</c> to serialize such fields.

     /// </para>

     /// </remarks>

     public sealed partial class CodedOutputStream