[gtk+/gtk-3-22] demos: Fix build

[Chun-wei Fan <fanchunwei src gnome org>]

commit 1063460db2d662681ef90c0daa3c1739620c650f
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Jan 20 18:17:33 2017 +0800

    demos: Fix build
    
    Include gtk/fallback-c89.c so that we can ensure that we have round(), and
    that file already includes math.h

 demos/gtk-demo/gtkfishbowl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/gtkfishbowl.c b/demos/gtk-demo/gtkfishbowl.c
index 54ee7b0..4f2a2d5 100644
--- a/demos/gtk-demo/gtkfishbowl.c
+++ b/demos/gtk-demo/gtkfishbowl.c
@@ -19,7 +19,7 @@
 
 #include "gtkfishbowl.h"
 
-#include <math.h>
+#include "gtk/fallback-c89.c"
 
 typedef struct _GtkFishbowlPrivate       GtkFishbowlPrivate;
 typedef struct _GtkFishbowlChild         GtkFishbowlChild;