lookahead cost map: remove unused member

Signed-off-by: Alessandro Comodi <[email protected]>

Author: acomodi

vpr/src/route/router_lookahead_cost_map.h

@@ -100,8 +100,6 @@ class CostMap {
                                  ///<delta locations that fall outside of a segment's bounding box.
                                  ///<The penalty map is addressed as follows penalty_[0][segment_index]
 
-    size_t seg_count_; ///<Total segment count in the architecture
-
     /**
      * @brief Get penalty delay for a segment type
      * @param matrix cost map for a specific segment type