re #13613 rb4516 Tunables needs volatile keyword

*** 18,27 ****
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
   */
  
  /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  /*      All Rights Reserved   */
  
*** 1580,1590 ****
  extern void     nfs4_destroy_dot_entries(void);
  extern struct nfs4_callback_globals     *nfs4_get_callback_globals(void);
  
  extern struct nfs4_server nfs4_server_lst;
  
! extern clock_t nfs_write_error_interval;
  
  #endif /* _KERNEL */
  
  /*
   * Flags for nfs4getfh_otw.
--- 1581,1591 ----
  extern void     nfs4_destroy_dot_entries(void);
  extern struct nfs4_callback_globals     *nfs4_get_callback_globals(void);
  
  extern struct nfs4_server nfs4_server_lst;
  
! extern volatile clock_t nfs_write_error_interval;
  
  #endif /* _KERNEL */
  
  /*
   * Flags for nfs4getfh_otw.