re #13613 rb4516 Tunables needs volatile keyword

@@ -20,10 +20,13 @@
  */
 /*
  * 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>

@@ -57,12 +60,10 @@
 #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 *);