re #13613 rb4516 Tunables needs volatile keyword

*** 20,29 ****
--- 20,32 ----
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
+ /*
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  */
  
  #include <sys/types.h>
  #include <sys/systm.h>
  #include <sys/param.h>
  #include <sys/user.h>
*** 57,68 ****
  #include <sys/cpc_pcbe.h>
  #include <sys/kstat.h>
  #include <sys/socketvar.h>
  #include <sys/kiconv.h>
  
- extern int moddebug;
- 
  extern struct cb_ops no_cb_ops;
  extern struct dev_ops nodev_ops;
  extern struct dev_ops mod_nodev_ops;
  
  extern struct modctl *mod_getctl(struct modlinkage *);
--- 60,69 ----