5045 use atomic_{inc,dec}_* instead of atomic_add_*

*** 119,138 ****
   * Put a hold on a label structure.
   */
  void
  label_hold(ts_label_t *lab)
  {
!         atomic_add_32(&lab->tsl_ref, 1);
  }
  
  /*
   * Release previous hold on a label structure.  Free it if refcnt == 0.
   */
  void
  label_rele(ts_label_t *lab)
  {
!         if (atomic_add_32_nv(&lab->tsl_ref, -1) == 0)
                  kmem_cache_free(tslabel_cache, lab);
  }
  
  bslabel_t *
  label2bslabel(ts_label_t *lab)
--- 119,138 ----
   * Put a hold on a label structure.
   */
  void
  label_hold(ts_label_t *lab)
  {
!         atomic_inc_32(&lab->tsl_ref);
  }
  
  /*
   * Release previous hold on a label structure.  Free it if refcnt == 0.
   */
  void
  label_rele(ts_label_t *lab)
  {
!         if (atomic_dec_32_nv(&lab->tsl_ref) == 0)
                  kmem_cache_free(tslabel_cache, lab);
  }
  
  bslabel_t *
  label2bslabel(ts_label_t *lab)