[calls] Drop use of volatile

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 44c892b6f7bdb489e19e225b74788d1c3d0f4dff
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Sat Jul 9 11:29:26 2022 +0200

    Drop use of volatile
    
    The volatile qualifier was mostly used for historical reasons,
    the documentation for `g_once_init_enter()` and `g_once_init_leave()`
    has the following to say:
    
    While `location` has a `volatile` qualifier,
    this is a historical artifact and the pointer passed to it
    should not be volatile.
    
    See also https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1719

 src/gtklistmodels/gtktypebuiltins.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/gtklistmodels/gtktypebuiltins.c b/src/gtklistmodels/gtktypebuiltins.c
index fef1b283..29d40eeb 100644
--- a/src/gtklistmodels/gtktypebuiltins.c
+++ b/src/gtklistmodels/gtktypebuiltins.c
@@ -7,7 +7,7 @@
 GType
 gtk_sorter_order_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+  static gsize g_define_type_id__volatile = 0;
 
   if (g_once_init_enter (&g_define_type_id__volatile))
     {
@@ -27,7 +27,7 @@ gtk_sorter_order_get_type (void)
 GType
 gtk_sorter_change_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+  static gsize g_define_type_id__volatile = 0;
 
   if (g_once_init_enter (&g_define_type_id__volatile))
     {
@@ -50,7 +50,7 @@ gtk_sorter_change_get_type (void)
 GType
 gtk_filter_match_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+  static gsize g_define_type_id__volatile = 0;
 
   if (g_once_init_enter (&g_define_type_id__volatile))
     {
@@ -70,7 +70,7 @@ gtk_filter_match_get_type (void)
 GType
 gtk_filter_change_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+  static gsize g_define_type_id__volatile = 0;
 
   if (g_once_init_enter (&g_define_type_id__volatile))
     {