if_clone.c allows creating multiple interfaces with the same name

Hi All,

Recently I've discovered a bug in if_clone.c and if.c where the code allows 
multiple interfaces to be created with exactly the same name (which leads to 
all sorts of other interesting problems).
I've submitted a PR about this with patches, which can be found here :

	http://www.freebsd.org/cgi/query-pr.cgi?pr=162789

Could anyone take a look at it?


Regards,
-- 
Daan Vreeken
Vitsch Electronics
http://Vitsch.nl
tel: +31-(0)40-7113051 / +31-(0)6-46210825
KvK nr: 17174380