[glib] docs: Remove some latent DocBook usage in the GObjectClass documentation

[Philip Withnall <pwithnall src gnome org>]

commit 7c2fd10fe4557fcfc0a950f82a46d9f27688f708
Author: Philip Withnall <withnall endlessm com>
Date:   Fri Jan 5 16:44:18 2018 +0000

    docs: Remove some latent DocBook usage in the GObjectClass documentation
    
    Replace it with gtk-doc syntax.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 gobject/gobject.h |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/gobject/gobject.h b/gobject/gobject.h
index 1a6c969..9830663 100644
--- a/gobject/gobject.h
+++ b/gobject/gobject.h
@@ -287,9 +287,8 @@ struct  _GObject
  * 
  * The class structure for the GObject type.
  * 
- * <example>
- * <title>Implementing singletons using a constructor</title>
- * <programlisting>
+ * |[<!-- language="C" -->
+ * // Example of implementing a singleton using a constructor.
  * static MySingleton *the_singleton = NULL;
  * 
  * static GObject*
@@ -311,7 +310,7 @@ struct  _GObject
  * 
  *   return object;
  * }
- * </programlisting></example>
+ * ]|
  */
 struct  _GObjectClass
 {