gtk/ui: Introduce helper gd_update_scale

The code snippet updating scale_x/scale_y is general and will be used in
next patch. Make it a function.

Signed-off-by: Weifeng Liu <weifeng.liu.z@gmail.com>
Message-ID: <20250511073337.876650-4-weifeng.liu.z@gmail.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2 files changed