txd: Remove write-only variable in txd_decode_frame().

libavcodec/txd.c:49:60: warning: variable ‘mipmap_count’ set but not used

libavcodec/txd.c

@@ -46,7 +46,7 @@ static int txd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     GetByteContext gb;
     AVFrame *picture = data;
     AVFrame * const p = &s->picture;
-    unsigned int version, w, h, d3d_format, depth, stride, mipmap_count, flags;
+    unsigned int version, w, h, d3d_format, depth, stride, flags;
     unsigned int y, v;
     uint8_t *ptr;
     uint32_t *pal;
@@ -58,8 +58,7 @@ static int txd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     w               = bytestream2_get_le16(&gb);
     h               = bytestream2_get_le16(&gb);
     depth           = bytestream2_get_byte(&gb);
-    mipmap_count    = bytestream2_get_byte(&gb);
-    bytestream2_skip(&gb, 1);
+    bytestream2_skip(&gb, 2);
     flags           = bytestream2_get_byte(&gb);
 
     if (version < 8 || version > 9) {