twn_input.c: remove input_mouse_captured(), add ctx.mouse_capture

apps/demos/scenery/scenes/ingame.c

@@ -216,7 +216,7 @@ static void ingame_tick(State *state) {
     if (input_action_just_pressed("mouse_capture_toggle"))
         scn->mouse_captured = !scn->mouse_captured;
 
-    input_mouse_captured(scn->mouse_captured);
+    ctx.mouse_capture = scn->mouse_captured;
 
     generate_terrain(scn);
     draw_terrain(scn);