mov: use designated initializers for AVClass

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavformat/mov.c

@@ -3152,8 +3152,13 @@ static const AVOption options[] = {
         0, 1, AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_DECODING_PARAM},
     {NULL}
 };
-static const AVClass class = {"mov,mp4,m4a,3gp,3g2,mj2", av_default_item_name, options, LIBAVUTIL_VERSION_INT};
 
+static const AVClass class = {
+    .class_name = "mov,mp4,m4a,3gp,3g2,mj2",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
 
 AVInputFormat ff_mov_demuxer = {
     .name           = "mov,mp4,m4a,3gp,3g2,mj2",