Cursor image and checksum go hand in hand. Update both in the same
place. The helper cannot fail, so remove the return type.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702115029.5281-5-tzimmermann@suse.de