VAAPI-X11: remove unused member from picture_sys_t

modules/codec/avcodec/vaapi.h

@@ -87,9 +87,6 @@ typedef struct
 /* picture_sys_t */
 struct picture_sys_t
 {
-    /* */
-    vlc_object_t     *obj;
-
     /* Link surface with picture_sys_t permanently */
     VASurfaceID  i_id;
     int          i_refcount;

modules/codec/avcodec/vaapi_x11.c

@@ -1374,7 +1374,6 @@ static picture_pool_t *Pool (vout_display_t *vd, unsigned requested_count)
         pic_sys->i_id = VA_INVALID_SURFACE;
         pic_sys->i_refcount = 0;
         pic_sys->i_cache = 0;
-        pic_sys->obj = VLC_OBJECT(vd);
 
         pic_array[count] = pic;
         pic_array[count]->b_progressive = true;