[gnome-commander/ConvertWarningsToErrors] Adds format attribute to method definition to suppress suggest-attribute=format warning

[Uwe Scholz <uwescholz src gnome org>]

commit 961ec0b949cc695008437965f3607f4b4fce53ff
Author: Uwe Scholz <uwescholz src gnome org>
Date:   Fri Apr 21 22:14:11 2017 +0200

    Adds format attribute to method definition to suppress suggest-attribute=format warning

 libgcmd/libgcmd-widget-factory.cc |    1 -
 libgcmd/libgcmd-widget-factory.h  |    6 +++++-
 src/tags/gnome-cmd-tags.h         |    2 +-
 3 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/libgcmd/libgcmd-widget-factory.cc b/libgcmd/libgcmd-widget-factory.cc
index e4330e0..df22378 100644
--- a/libgcmd/libgcmd-widget-factory.cc
+++ b/libgcmd/libgcmd-widget-factory.cc
@@ -521,7 +521,6 @@ static void on_response (GtkDialog *dialog, gint id, gpointer data)
     gtk_widget_destroy (GTK_WIDGET (dialog));
 }
 
-
 void create_error_dialog (const gchar *msg, ...)
 {
     va_list      argptr;
diff --git a/libgcmd/libgcmd-widget-factory.h b/libgcmd/libgcmd-widget-factory.h
index 8a977a2..6315d7e 100644
--- a/libgcmd/libgcmd-widget-factory.h
+++ b/libgcmd/libgcmd-widget-factory.h
@@ -166,6 +166,10 @@ void progress_bar_update (GtkWidget *pbar, gint max);
 
 const char *get_entry_text (GtkWidget *parent, const gchar *entry_name);
 
-void create_error_dialog (const gchar *msg, ...);
+#ifdef __GNUC__
+    void create_error_dialog (const gchar *msg, ...) __attribute__ ((format (gnu_printf, 1, 2)));
+#else
+    void create_error_dialog (const gchar *msg, ...);
+#endif
 
 #endif //__LIBGCMD_WIDGET_FACTORY_H__
diff --git a/src/tags/gnome-cmd-tags.h b/src/tags/gnome-cmd-tags.h
index 57fbae9..05efbb7 100644
--- a/src/tags/gnome-cmd-tags.h
+++ b/src/tags/gnome-cmd-tags.h
@@ -546,7 +546,7 @@ class GnomeCmdFileMetadata
 #ifdef __GNUC__
     void addf (const GnomeCmdTag tag, const gchar *fmt, ...) __attribute__ ((format (gnu_printf, 3, 4)));
 #else
-    void addf (const GnomeCmdTag tag, const gchar *fmt, ...)
+    void addf (const GnomeCmdTag tag, const gchar *fmt, ...);
 #endif
     gboolean has_tag (const GnomeCmdTag tag);