Add newlines. Use __func__ instead of hardcoded name (fixes one case).
While here, wrap lines according to style(9).
Differential Revision: https://reviews.freebsd.org/D51357
For developers gensnmptree can now generate functions for enums to convert
between enums and strings and to check the validity of a value.
The sources in FreeBSD are now in sync with the upstream which allows to
bring in IPv6 modifications.
Gleb Smirnoff