XXX removed ill_null symbol

@@ -98,11 +98,10 @@
 ilb_sticky_hash_size
 ilb_sticky_expiry
 ilb_sticky_timer_size
 ilb_sticky_timeout
 ill_no_arena
-ill_null
 inet_dev_info
 inet_devops
 ip6_ftable_hash_size
 ip6opt_ls
 ip_cgtp_filter_rev