- Comment out NULL, NULL barrier for Unix domain sockets section as the

double NULL entries signal Witness to stop processing the array of
  order entries meaning none of the spin locks are added resulting in
  panics on boot.
- Add a missing NULL, NULL terminator to the Slip locks list to keep them
  separate from the spin locks.

sys/kern/subr_witness.c

@@ -283,8 +283,8 @@ static struct witness_order_list_entry order_lists[] = {
 	{ NULL, NULL },
 	/*
 	 * UNIX Domain Sockets
-	 */
 	{ NULL, NULL },
+	 */
 	/*
 	 * UDP/IP
 	 */
@@ -302,6 +302,7 @@ static struct witness_order_list_entry order_lists[] = {
 	 */
 	{ "slip_mtx", &lock_class_mtx_sleep },
 	{ "slip sc_mtx", &lock_class_mtx_sleep },
+	{ NULL, NULL },
 	/*
 	 * spin locks
 	 */