printing: Fix memory leak when listing Avahi printers
printing: Fix memory leak when listing Avahi printers

Return values of g_variant_get_child_value() were not unreffed
correctly together with one value returned by g_variant_get().
Use g_variant_get_data() instead of copying each byte separately.

https://bugzilla.gnome.org/show_bug.cgi?id=712799

msteinert/gtk,jessevdk/gtk,Sidnioulz/SandboxGtk,Sidnioulz/SandboxGtk,jadahl/gtk,alexlarsson/gtk,jadahl/gtk,jadahl/gtk,jigpu/gtk,davidgumberg/gtk,grubersjoe/adwaita,davidgumberg/gtk,ahodesuka/gtk,davidgumberg/gtk,jigpu/gtk,jessevdk/gtk,chergert/gtk,Adamovskiy/gtk,davidgumberg/gtk,alexlarsson/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,chergert/gtk,alexlarsson/gtk,Lyude/gtk-,chergert/gtk,Lyude/gtk-,Adamovskiy/gtk,Adamovskiy/gtk,Adamovskiy/gtk,jessevdk/gtk,jadahl/gtk,alexlarsson/gtk,grubersjoe/adwaita,Lyude/gtk-,chergert/gtk,Adamovskiy/gtk,alexlarsson/gtk,jadahl/gtk,jigpu/gtk,alexlarsson/gtk,jigpu/gtk,grubersjoe/adwaita,jessevdk/gtk,jadahl/gtk,Lyude/gtk-,jessevdk/gtk,grubersjoe/adwaita,davidgumberg/gtk,grubersjoe/adwaita,chergert/gtk,davidgumberg/gtk,jessevdk/gtk,msteinert/gtk,Lyude/gtk-,Adamovskiy/gtk,ahodesuka/gtk,jigpu/gtk,ahodesuka/gtk,ahodesuka/gtk,chergert/gtk,jigpu/gtk,ahodesuka/gtk,grubersjoe/adwaita,jessevdk/gtk,jadahl/gtk,msteinert/gtk,alexlarsson/gtk,Sidnioulz/SandboxGtk,Lyude/gtk-,Sidnioulz/SandboxGtk,ahodesuka/gtk,davidgumberg/gtk,ahodesuka/gtk,msteinert/gtk,msteinert/gtk,ahodesuka/gtk,Lyude/gtk-,chergert/gtk,Adamovskiy/gtk,chergert/gtk,Lyude/gtk-,jigpu/gtk,grubersjoe/adwaita,alexlarsson/gtk,Adamovskiy/gtk,msteinert/gtk,grubersjoe/adwaita,davidgumberg/gtk,Sidnioulz/SandboxGtk