Followup cleanup

Ifdef the functions too, otherwise they will cause the compiler
to complain about unused statics when building without X.

https://bugzilla.gnome.org/show_bug.cgi?id=728672

panels/info/cc-info-panel.c

@@ -290,6 +290,7 @@ graphics_data_free (GraphicsData *gdata)
   g_slice_free (GraphicsData, gdata);
 }
 
+#ifdef GDK_WINDOWING_X11
 static char *
 get_graphics_data_glx_renderer ()
 {
@@ -422,6 +423,7 @@ get_graphics_data_xorg_vesa_hardware (void)
 
   return result;
 }
+#endif
 
 static GraphicsData *
 get_graphics_data (void)