docs: Remove <!-- --> comment before plural s

These did show up in the html. Since symbol names are checked for a
trailing plural s when generating the docs, the links stay functional
after removing these comments.

https://bugzilla.gnome.org/show_bug.cgi?id=728380

gobject/gclosure.h

@@ -102,7 +102,7 @@ typedef void  (*GClosureNotify)		(gpointer	 data,
  *  value.
  * @n_param_values: the length of the @param_values array
  * @param_values: (array length=n_param_values): an array of
- *  #GValue<!-- -->s holding the arguments on which to invoke the
+ *  #GValues holding the arguments on which to invoke the
  *  callback of @closure
  * @invocation_hint: (allow-none): the invocation hint given as the
  *  last argument to g_closure_invoke()

gobject/gtype.h

@@ -926,7 +926,7 @@ typedef void   (*GInterfaceFinalizeFunc)     (gpointer         g_iface,
  * whether they actually want to cache the class of this type, since all
  * classes are routed through the same #GTypeClassCacheFunc chain.
  * 
- * Returns: %TRUE to stop further #GTypeClassCacheFunc<!-- -->s from being 
+ * Returns: %TRUE to stop further #GTypeClassCacheFuncs from being 
  *  called, %FALSE to continue.
  */
 typedef gboolean (*GTypeClassCacheFunc)	     (gpointer	       cache_data,

gobject/gvaluecollector.h

@@ -244,7 +244,7 @@ G_STMT_START {										\
 /**
  * G_VALUE_COLLECT_FORMAT_MAX_LENGTH:
  * 
- * The maximal number of #GTypeCValue<!-- -->s which can be collected for a 
+ * The maximal number of #GTypeCValues which can be collected for a 
  * single #GValue.
  */
 #define	G_VALUE_COLLECT_FORMAT_MAX_LENGTH	(8)