trace.h: include stdio.h only if trace is enabled

private-include/trace.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright 2012 Institute of Communication and Computer Systems (ICCS) 
+ *   Copyright Institute of Communication and Computer Systems (ICCS) 
  *
  *   Licensed under the Apache License, Version 2.0 (the "License");
  *   you may not use this file except in compliance with the License.
@@ -26,9 +26,10 @@
 #define TRACE_H
 #include "dmm_config.h"
 
+#if TRACE_LEVEL >= 1
+
 #include <stdio.h>
 
-#if TRACE_LEVEL >= 1
 /** Function for Level 1 trace messages */
 #define TRACE_1(...) fprintf(stderr, __VA_ARGS__)
 #else /* TRACE_LEVEL >= 1 */