no need for state in light sensor demo

watch-faces/demo/light_sensor_face.h

@@ -38,11 +38,6 @@
  *
  */
 
-typedef struct {
-    // Anything you need to keep track of, put it here!
-    uint8_t unused;
-} light_sensor_state_t;
-
 void light_sensor_face_setup(uint8_t watch_face_index, void ** context_ptr);
 void light_sensor_face_activate(void *context);
 bool light_sensor_face_loop(movement_event_t event, void *context);