netfilter: ipset: Check extensions attributes before getting extensions.

Make all extensions attributes checks within ip_set_get_extensions()
and reduce number of duplicated code.

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
16 files changed