[gnome-control-center] datetime: Replace ifdefs with #pragma once

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 9bc6d2d3f1ba78d06dc73856919391b1fa79bdb1
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Nov 21 20:33:29 2019 +1300

    datetime: Replace ifdefs with #pragma once

 panels/datetime/cc-datetime-panel.h | 6 +-----
 panels/datetime/cc-timezone-map.h   | 6 +-----
 panels/datetime/tz.h                | 8 ++++----
 3 files changed, 6 insertions(+), 14 deletions(-)
---
diff --git a/panels/datetime/cc-datetime-panel.h b/panels/datetime/cc-datetime-panel.h
index 29c0498b2..a726e6bb4 100644
--- a/panels/datetime/cc-datetime-panel.h
+++ b/panels/datetime/cc-datetime-panel.h
@@ -18,9 +18,7 @@
  *
  */
 
-
-#ifndef _CC_DATE_TIME_PANEL_H
-#define _CC_DATE_TIME_PANEL_H
+#pragma once
 
 #include <shell/cc-panel.h>
 
@@ -30,5 +28,3 @@ G_BEGIN_DECLS
 G_DECLARE_FINAL_TYPE (CcDateTimePanel, cc_date_time_panel, CC, DATE_TIME_PANEL, CcPanel)
 
 G_END_DECLS
-
-#endif /* _CC_DATE_TIME_PANEL_H */
diff --git a/panels/datetime/cc-timezone-map.h b/panels/datetime/cc-timezone-map.h
index bf6cbc2f0..f4c99e5bd 100644
--- a/panels/datetime/cc-timezone-map.h
+++ b/panels/datetime/cc-timezone-map.h
@@ -18,9 +18,7 @@
  *
  */
 
-
-#ifndef _CC_TIMEZONE_MAP_H
-#define _CC_TIMEZONE_MAP_H
+#pragma once
 
 #include <gtk/gtk.h>
 #include "tz.h"
@@ -39,5 +37,3 @@ void cc_timezone_map_set_bubble_text (CcTimezoneMap *map,
 TzLocation * cc_timezone_map_get_location (CcTimezoneMap *map);
 
 G_END_DECLS
-
-#endif /* _CC_TIMEZONE_MAP_H */
diff --git a/panels/datetime/tz.h b/panels/datetime/tz.h
index 96b25140c..a2376f8a4 100644
--- a/panels/datetime/tz.h
+++ b/panels/datetime/tz.h
@@ -21,12 +21,12 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
-
-#ifndef _E_TZ_H
-#define _E_TZ_H
+#pragma once
 
 #include <glib.h>
 
+G_BEGIN_DECLS
+
 #ifndef __sun
 #  define TZ_DATA_FILE "/usr/share/zoneinfo/zone.tab"
 #else
@@ -89,4 +89,4 @@ void       tz_info_free               (TzInfo *tz_info);
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (TzDB, tz_db_free)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (TzInfo, tz_info_free)
 
-#endif
+G_END_DECLS