infobar: Remove unneeded checks
infobar: Remove unneeded checks

Size vfuncs always get non-null out variables passed, so no need to
check for NULL.

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