iconcache: Ensure we don't lose data on power loss
iconcache: Ensure we don't lose data on power loss

fsync() should ensure our data hits disk; since corrupt icon
caches break all apps, we need to ensure it's valid.

https://bugzilla.gnome.org/show_bug.cgi?id=635307

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