re #13613 rb4516 Tunables needs volatile keyword

@@ -2158,14 +2158,14 @@
                 nfs_rw_exit(&svp->sv_lock);
         }
         return (svp);
 }
 
-static ushort_t nfs4_max_threads = 8;   /* max number of active async threads */
-uint_t nfs4_bsize = 32 * 1024;  /* client `block' size */
-static uint_t nfs4_async_clusters = 1;  /* # of reqs from each async queue */
-static uint_t nfs4_cots_timeo = NFS_COTS_TIMEO;
+volatile ushort_t nfs4_max_threads = 8; /* max number of active async threads */
+volatile uint_t nfs4_bsize = 32 * 1024; /* client `block' size */
+volatile uint_t nfs4_async_clusters = 1; /* # of reqs from each async queue */
+volatile uint_t nfs4_cots_timeo = NFS_COTS_TIMEO;
 
 /*
  * Remap the root filehandle for the given filesystem.
  *
  * results returned via the nfs4_error_t parameter.