iptables: correctly check for too-long chain/target/match names

* iptables-restore was not checking for chain name length
* iptables was not checking for match name length
* target length was checked against 32, not 29.

References: http://bugzilla.netfilter.org/show_bug.cgi?id=641
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
5 files changed