iconview: Use set_[hv]adjustment_values() also when just changing upper
iconview: Use set_[hv]adjustment_values() also when just changing upper

Simplifies the code quite a bit and the code is smart enough to not do
extra work if only one value changes.

grubersjoe/adwaita,davidt/gtk,Lyude/gtk-,jessevdk/gtk,grubersjoe/adwaita,Adamovskiy/gtk,ahodesuka/gtk,simokivimaki/gtk,jadahl/gtk,msteinert/gtk,davidt/gtk,alexlarsson/gtk,Distrotech/gtk2,jadahl/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,grubersjoe/adwaita,chergert/gtk,Adamovskiy/gtk,Adamovskiy/gtk,simokivimaki/gtk,davidgumberg/gtk,bratsche/gtk-,Lyude/gtk-,ahodesuka/gtk,jessevdk/gtk,jessevdk/gtk,Distrotech/gtk2,jigpu/gtk,ebassi/gtk,simokivimaki/gtk,jadahl/gtk,Distrotech/gtk2,ebassi/gtk,chergert/gtk,ebassi/gtk,Lyude/gtk-,davidgumberg/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,davidt/gtk,Sidnioulz/SandboxGtk,msteinert/gtk,chergert/gtk,ebassi/gtk,Distrotech/gtk2,chergert/gtk,msteinert/gtk,Lyude/gtk-,simokivimaki/gtk,alexlarsson/gtk,grubersjoe/adwaita,bratsche/gtk-,alexlarsson/gtk,simokivimaki/gtk,Adamovskiy/gtk,bratsche/gtk-,jigpu/gtk,jadahl/gtk,jessevdk/gtk,Distrotech/gtk2,davidgumberg/gtk,ebassi/gtk,grubersjoe/adwaita,jessevdk/gtk,jigpu/gtk,chergert/gtk,jigpu/gtk,davidt/gtk,chergert/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,chergert/gtk,chergert/gtk,alexlarsson/gtk,Lyude/gtk-,simokivimaki/gtk,jadahl/gtk,davidt/gtk,alexlarsson/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,msteinert/gtk,jigpu/gtk,jigpu/gtk,alexlarsson/gtk,Lyude/gtk-,jigpu/gtk,ahodesuka/gtk,jadahl/gtk,bratsche/gtk-,msteinert/gtk,jadahl/gtk,ahodesuka/gtk,davidgumberg/gtk,grubersjoe/adwaita,ebassi/gtk,msteinert/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jadahl/gtk,davidgumberg/gtk,bratsche/gtk-,alexlarsson/gtk,grubersjoe/adwaita,Adamovskiy/gtk,ahodesuka/gtk,jigpu/gtk,Lyude/gtk-,davidgumberg/gtk,alexlarsson/gtk,davidgumberg/gtk,jessevdk/gtk,Distrotech/gtk2,ahodesuka/gtk,davidgumberg/gtk,Adamovskiy/gtk,bratsche/gtk-,davidt/gtk,Sidnioulz/SandboxGtk,jessevdk/gtk