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

*** 676,686 ****
  
          if (ret == DDI_SUCCESS) {
                  dup_hdlp = (ddi_intr_handle_impl_t *)
                      kmem_alloc(sizeof (ddi_intr_handle_impl_t), KM_SLEEP);
  
!                 atomic_add_32(&hdlp->ih_dup_cnt, 1);
  
                  *dup = (ddi_intr_handle_t)dup_hdlp;
                  bcopy(hdlp, dup_hdlp, sizeof (ddi_intr_handle_impl_t));
  
                  /* These fields are unique to each dupped msi-x vector */
--- 676,686 ----
  
          if (ret == DDI_SUCCESS) {
                  dup_hdlp = (ddi_intr_handle_impl_t *)
                      kmem_alloc(sizeof (ddi_intr_handle_impl_t), KM_SLEEP);
  
!                 atomic_inc_32(&hdlp->ih_dup_cnt);
  
                  *dup = (ddi_intr_handle_t)dup_hdlp;
                  bcopy(hdlp, dup_hdlp, sizeof (ddi_intr_handle_impl_t));
  
                  /* These fields are unique to each dupped msi-x vector */