avcodec/exr: remove unneed scanline_size var

libavcodec/exr.c

@@ -122,7 +122,6 @@ typedef struct EXRContext {
     uint32_t ymax, ymin;
     uint32_t xdelta, ydelta;
 
-    uint64_t scan_line_size;
     int scan_lines_per_block;
 
     EXRTileAttribute tile_attr; /* header data attribute of tile */
@@ -1524,8 +1523,6 @@ static int decode_header(EXRContext *s)
         }
     }
 
-    s->scan_line_size = s->xdelta * s->current_channel_offset;
-
     if (bytestream2_get_bytes_left(&s->gb) <= 0) {
         av_log(s->avctx, AV_LOG_ERROR, "Incomplete frame.\n");
         return AVERROR_INVALIDDATA;