[glib] docs: Mention pointer semantics for g_array_set_clear_func()

[Philip Withnall <pwithnall src gnome org>]

commit 90d3337e1d9d8218f1f8509417b6ae65993aa029
Author: Philip Withnall <withnall endlessm com>
Date:   Fri Feb 23 19:23:27 2018 +0000

    docs: Mention pointer semantics for g_array_set_clear_func()
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    Reviewed-by: nobody

 glib/garray.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/glib/garray.c b/glib/garray.c
index 5670408fd..aa3c04707 100644
--- a/glib/garray.c
+++ b/glib/garray.c
@@ -220,7 +220,8 @@ g_array_sized_new (gboolean zero_terminated,
  *
  * The @clear_func will be called when an element in the array
  * data segment is removed and when the array is freed and data
- * segment is deallocated as well.
+ * segment is deallocated as well. @clear_func will be passed a
+ * pointer to the element to clear, rather than the element itself.
  *
  * Note that in contrast with other uses of #GDestroyNotify
  * functions, @clear_func is expected to clear the contents of