Update source.cs (dotnet#8807)

Author: vanillajonathan

snippets/csharp/System.Xml.Serialization/XmlSerializer/CanDeserialize/source.cs

@@ -8,15 +8,15 @@ public class Sample
 // <Snippet1>
 private void TestDocument(string filename, Type objType)
 {
-   // Using a FileStream, create an XmlTextReader.
-   Stream fs = new FileStream(filename, FileMode.Open);
-   XmlReader reader = new XmlTextReader(fs);
-   XmlSerializer serializer = new XmlSerializer(objType);
-   if(serializer.CanDeserialize(reader))
-      {
-         Object o = serializer.Deserialize(reader);
-      }
-   fs.Close();
+    // Using a FileStream, create an XmlTextReader.
+    Stream fs = new FileStream(filename, FileMode.Open);
+    XmlReader reader = new XmlTextReader(fs);
+    XmlSerializer serializer = new XmlSerializer(objType);
+    if (serializer.CanDeserialize(reader))
+    {
+        Object o = serializer.Deserialize(reader);
+    }
+    fs.Close();
 }
 
 // </Snippet1>