kern/155227: netflow.c does not compile with disabled INET6

[bz at FreeBSD.org]

Synopsis: netflow.c does not compile with disabled INET6

Responsible-Changed-From-To: freebsd-bugs->bz
Responsible-Changed-By: bz
Responsible-Changed-When: Thu Mar 3 15:02:13 UTC 2011
Responsible-Changed-Why: 
I noticed last night and am waiting for compiles to finish to commit
the fix.

http://www.freebsd.org/cgi/query-pr.cgi?pr=155227