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

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

commit 3a95330b1750fca8bab5101a73d46ad065695ed9
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Nov 21 20:40:07 2019 +1300

    search-provider: Replace ifdefs with #pragma once

 search-provider/control-center-search-provider.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/search-provider/control-center-search-provider.h 
b/search-provider/control-center-search-provider.h
index ead38e861..3dc058fa5 100644
--- a/search-provider/control-center-search-provider.h
+++ b/search-provider/control-center-search-provider.h
@@ -17,14 +17,15 @@
  *
  */
 
-#ifndef _CONTROL_CENTER_SEARCH_PROVIDER_H
-#define _CONTROL_CENTER_SEARCH_PROVIDER_H
+#pragma once
 
 #include <gtk/gtk.h>
 
 #include <shell/cc-shell-model.h>
 #include "cc-search-provider.h"
 
+G_BEGIN_DECLS
+
 typedef struct {
   GtkApplication parent;
 
@@ -48,4 +49,4 @@ CcSearchProviderApp *cc_search_provider_app_get (void);
 
 CcShellModel *cc_search_provider_app_get_model (CcSearchProviderApp *application);
 
-#endif
+G_END_DECLS