XmlName is a value type therefore can never be null. mcs picked this …

…up as a warning.

src/Castle.Core.Tests/Components.DictionaryAdapter.Tests/Xml/XmlApis/MockXmlIncludedTypeMap.cs

@@ -36,7 +36,7 @@ public MockXmlIncludedTypeMap()
 
 		public bool TryGet(XmlName xsiType, out IXmlIncludedType includedType)
 		{
-			return (xsiType == null || xsiType == Default.XsiType)
+			return (xsiType == Default.XsiType)
 				? Try.Success(out includedType, Default)
 				: includedTypes.TryGet(xsiType, out includedType);
 		}