ChangeSet@1.1935.1.4, 2004-09-19 00:05:29+02:00, kaber@coreworks.de
  [NETFILTER]: kill struct ip_nat_hash, saves two pointers per conntrack
 
  The back-pointer is not needed when using list.h macros.
 
  Signed-off-by: Patrick McHardy <kaber@trash.net>