[at-spi2-core] Use the appropriate annotation

[Emmanuele Bassi <ebassi src gnome org>]

commit 1110739743ac543118bb8dce8532be8b4476aa94
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu May 17 15:30:52 2018 +0100

    Use the appropriate annotation
    
    This avoids a warning for a unused-but-set variable.

 registryd/reentrant-list.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/registryd/reentrant-list.c b/registryd/reentrant-list.c
index 29bdfca..7f9a716 100644
--- a/registryd/reentrant-list.c
+++ b/registryd/reentrant-list.c
@@ -45,7 +45,7 @@ spi_re_entrant_list_delete_link (GList * const *element_ptr)
   GList     *next;
   GList     *element;
   gboolean   first_item;
-  GList *dummy; /* suppress warning */
+  GList *dummy G_GNUC_UNUSED;
 
   g_return_if_fail (element_ptr != NULL);