re #13613 rb4516 Tunables needs volatile keyword

*** 21,36 ****
  
  /*
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  #ifndef _SYS_CLOCK_TICK_H
  #define _SYS_CLOCK_TICK_H
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"
- 
  #include <sys/types.h>
  #include <sys/mutex.h>
  #include <sys/cpuvar.h>
  #include <sys/systm.h>
  #include <sys/cyclic.h>
--- 21,37 ----
  
  /*
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
+ /*
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  */
  
  #ifndef _SYS_CLOCK_TICK_H
  #define _SYS_CLOCK_TICK_H
  
  #include <sys/types.h>
  #include <sys/mutex.h>
  #include <sys/cpuvar.h>
  #include <sys/systm.h>
  #include <sys/cyclic.h>
*** 106,116 ****
  #pragma weak            sync_softint
  extern void             sync_softint(cpuset_t);
  extern void             clock_tick(kthread_t *, int);
  extern void             membar_sync(void);
  
! extern int              hires_tick;
  #endif  /* _KERNEL */
  
  #ifdef  __cplusplus
  }
  #endif
--- 107,117 ----
  #pragma weak            sync_softint
  extern void             sync_softint(cpuset_t);
  extern void             clock_tick(kthread_t *, int);
  extern void             membar_sync(void);
  
! extern volatile int     hires_tick;
  #endif  /* _KERNEL */
  
  #ifdef  __cplusplus
  }
  #endif