netfilter: ipset: Remove extra whitespaces in ip_set.h
Remove unnecessary whitespaces.
Ported from a patch proposed by Sergey Popovich <popovich_sergei@mail.ua>.
Suggested-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>