Revert "iconview: layout items immediately when setting a GtkTreeModel"
Revert "iconview: layout items immediately when setting a GtkTreeModel"

It makes GtkIconView segfault on GTK 2.24.

gtk_icon_view_expose() calls gtk_icon_view_layout() first thing if
there's a layout queued anyway, so we wouldn't end up in the same
situation causing the crash the original patch is supposed to fix.

This reverts commit 5a03f4a6a50237d86959f596dda143dfc2f040d1.

https://bugzilla.gnome.org/show_bug.cgi?id=663138

johne53/MB3Gtk-2,johne53/MB3Gtk-2,Distrotech/gtk,Distrotech/gtk,Distrotech/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,Unity-Technologies/gtk,Unity-Technologies/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,Distrotech/gtk,Distrotech/gtk