lavc/qdrw: Do not fail decoding valid Quickdraw images.

libavcodec/qdrw.c

@@ -153,7 +153,6 @@ static int decode_frame(AVCodecContext *avctx,
 
     bytestream2_init(&gbc, avpkt->data, avpkt->size);
     if (   bytestream2_get_bytes_left(&gbc) >= 552
-           && !check_header(gbc.buffer      , bytestream2_get_bytes_left(&gbc))
            &&  check_header(gbc.buffer + 512, bytestream2_get_bytes_left(&gbc) - 512)
        )
         bytestream2_skip(&gbc, 512);