Since 03cf150ff3, the only purpose of this
VOCTRL was to signal a redraw to the vo. It actualy could have been
removed in 531868fe0d, but this was
missed. The UPDATE_VIDEO flag is better anyway because it allows us to
handle a wide variety of options scattered around that require the VO to
update itself and redraw. We can remove both of the custom callbacks in
vo.c and only leave the VOCTRL_VO_OPTS_CHANGED one. Additionally, that
commit also introduced vo_set_want_redraw, but this is redundant and not
needed. The VOs that use VOCTRL_UPDATE_RENDER_OPTS already set
vo->want_redraw, and those are the only VOs where these options are
relevant in the first place. So we can remove this as well and just let
the big callback in player/command do everything.
073858fcdd