iptables: fix standard target

iptables: fix standard target

This regression was added by:

commit cd2f9bdbb7f9b737e5d640aafeb78bcd8e3a7adf
Author: Jan Engelhardt <jengelh@inai.de>
Date:   Tue Sep 4 05:24:47 2012 +0200

    iptables: support for target aliase

The result is that:

 iptables -I INPUT -j ACCEPT

says:

 iptables: No chain/target/match by that name.

This also breaks iptables-restore, of course. Jan, you'll have to explain me
how you have tested this.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>