[calls] util: Use pragma once instead of include guard

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit c6a8dcf1409260e7ddf804d2c69c6097d4c4d117
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Mon Dec 27 20:16:00 2021 +0100

    util: Use pragma once instead of include guard

 src/util.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
---
diff --git a/src/util.h b/src/util.h
index efc791e9..d2256457 100644
--- a/src/util.h
+++ b/src/util.h
@@ -22,8 +22,7 @@
  *
  */
 
-#ifndef CALLS__UTIL_H__
-#define CALLS__UTIL_H__
+#pragma once
 
 #include <gtk/gtk.h>
 
@@ -147,4 +146,3 @@ const char *get_call_icon_symbolic_name (gboolean inbound,
 
 G_END_DECLS
 
-#endif /* CALLS__UTIL_H__ */