xxan: Remove write-only variable in xan_decode_frame_type0().

libavcodec/xxan.c:293:13: warning: variable ‘corr_end’ set but not used

libavcodec/xxan.c

@@ -290,11 +290,8 @@ static int xan_decode_frame_type0(AVCodecContext *avctx)
     }
 
     if (corr_off) {
-        int corr_end, dec_size;
+        int dec_size;
 
-        corr_end = (s->gb.buffer_end - s->gb.buffer_start);
-        if (chroma_off > corr_off)
-            corr_end = chroma_off;
         bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
         dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
         if (dec_size < 0)