lavc: use designated initialisers for all codecs.

It's more readable and less prone to breakage.

libavcodec/lclenc.c

@@ -171,13 +171,13 @@ static av_cold int encode_end(AVCodecContext *avctx)
 }
 
 AVCodec ff_zlib_encoder = {
-    "zlib",
-    AVMEDIA_TYPE_VIDEO,
-    CODEC_ID_ZLIB,
-    sizeof(LclEncContext),
-    encode_init,
-    encode_frame,
-    encode_end,
+    .name           = "zlib",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_ZLIB,
+    .priv_data_size = sizeof(LclEncContext),
+    .init           = encode_init,
+    .encode         = encode_frame,
+    .close          = encode_end,
     .pix_fmts = (const enum PixelFormat[]) { PIX_FMT_BGR24, PIX_FMT_NONE },
     .long_name = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
 };