The commit 
e099a173573ce1ba171092aee7bb3c72ea686e59
(netfilter: netns nat: per-netns NAT table) renamed the
nat_table from __nat_table to nat_table without updating the
__RW_LOCK_UNLOCKED(__nat_table.lock).
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 static struct xt_table nat_table = {
        .name           = "nat",
        .valid_hooks    = NAT_VALID_HOOKS,
-       .lock           = __RW_LOCK_UNLOCKED(__nat_table.lock),
+       .lock           = __RW_LOCK_UNLOCKED(nat_table.lock),
        .me             = THIS_MODULE,
        .af             = AF_INET,
 };