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

*** 173,183 ****
  
          mutex_enter(&db->db_mtx);
          db->db_hash_next = h->hash_table[idx];
          h->hash_table[idx] = db;
          mutex_exit(DBUF_HASH_MUTEX(h, idx));
!         atomic_add_64(&dbuf_hash_count, 1);
  
          return (NULL);
  }
  
  /*
--- 173,183 ----
  
          mutex_enter(&db->db_mtx);
          db->db_hash_next = h->hash_table[idx];
          h->hash_table[idx] = db;
          mutex_exit(DBUF_HASH_MUTEX(h, idx));
!         atomic_inc_64(&dbuf_hash_count);
  
          return (NULL);
  }
  
  /*
*** 208,218 ****
                  ASSERT(dbf != NULL);
          }
          *dbp = db->db_hash_next;
          db->db_hash_next = NULL;
          mutex_exit(DBUF_HASH_MUTEX(h, idx));
!         atomic_add_64(&dbuf_hash_count, -1);
  }
  
  static arc_evict_func_t dbuf_do_evict;
  
  static void
--- 208,218 ----
                  ASSERT(dbf != NULL);
          }
          *dbp = db->db_hash_next;
          db->db_hash_next = NULL;
          mutex_exit(DBUF_HASH_MUTEX(h, idx));
!         atomic_dec_64(&dbuf_hash_count);
  }
  
  static arc_evict_func_t dbuf_do_evict;
  
  static void