[niepce] Suppress format warning in the debug print

[Hubert Figuière <hub src gnome org>]

commit d49c274ca8051a2f023917a2c5b527f168ef028e
Author: Hubert Figuière <hub figuiere net>
Date:   Sun Sep 25 17:07:25 2016 -0400

    Suppress format warning in the debug print

 src/fwk/base/debug.cpp |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/fwk/base/debug.cpp b/src/fwk/base/debug.cpp
index f6421b2..8dceb87 100644
--- a/src/fwk/base/debug.cpp
+++ b/src/fwk/base/debug.cpp
@@ -1,7 +1,7 @@
 /*
  * niepce - fwk/base/debug.cpp
  *
- * Copyright (C) 2007-2012 Hubert Figuiere
+ * Copyright (C) 2007-2016 Hubert Figuiere
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -133,7 +133,11 @@ static void _v2print(const char* prefix, const char* filen, int linen,
     snprintf(buf, 128, "(0x%lx) ", (unsigned long)pthread_self());
     fwrite(buf, 1, strlen(buf), stderr);
 
+    // the format has been checked.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
     fprintf(stderr, prefix, filen, linen);
+#pragma GCC diagnostic pop
 
     if(func) {
         fwrite(func, 1, strlen(func), stderr);