fixup: dummy implementation using macro

Author: polarvid

src/clock.c

@@ -116,10 +116,8 @@ static void _update_process_times(void)
 }
 
 #else
-static void _update_process_times(void)
-{
-    return ;
-}
+
+#define _update_process_times()
 #endif /* RT_TRACING_CPU_USAGE */
 
 /**