lcl: return an appropriate error code

libavcodec/lclenc.c

@@ -164,7 +164,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
     zret = deflateInit(&c->zstream, c->compression);
     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
-        return 1;
+        return AVERROR_UNKNOWN;
     }
 
     return 0;