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

@@ -1178,11 +1178,11 @@
         }
 
         xge_hal_fifo_dtr_post(ring->channelh, dtr);
 
         /* Update per-ring tx statistics */
-        atomic_add_64(&ring->tx_pkts, 1);
+        atomic_inc_64(&ring->tx_pkts);
         atomic_add_64(&ring->tx_bytes, sent_bytes);
 
         return (NULL);
 
 _exit_cleanup: