ui/console: optionally update after gfx switch

ui/console: optionally update after gfx switch

When switching to the dummy surface, we should also call gfx_update.
But when using GL, we shouldn't call it.

By making it an argument to displaychangelistener_gfx_switch(), it will
be explicit, and cannot be forgotten that easily.

Fixes: commit ebced091 ("console: save current scanout details")
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>