vo: wake up core when VO requests redraw

a74a324 returned responsibility of video
redraw back to playloop. The playloop is only run if something wakes up
the core.

However, the logic for VO requested redraw only wakes up the core when
in->want_redraw is false, which is only resetted by vo_redraw, called
from the core. This creates a situation where it can never wake up the
core, so redrawing never happens even when VO requests it.

efc44d0 caused the issue to surface
because it also throttles VO requested redraws, and in some cases results
in the above behavior.

Fix this by always waking up core when the VO requests redraw.

Author: na-na-hi

video/out/vo.c

@@ -1166,7 +1166,7 @@ static MP_THREAD_VOID vo_thread(void *ptr)
                 wakeup_core(vo);
             }
         }
-        if (vo->want_redraw && !in->want_redraw) {
+        if (vo->want_redraw) {
             in->want_redraw = true;
             wakeup_core(vo);
         }