Although this code is in contrib/ there is no active upstream.
Reviewed by: brooks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36047
1. define the CODE * as const
2. restructure function to eliminate warning about exiting with no return.
severity_map() never returns when it can't find an appropriate sysylog
facility, and it longjmp()'s away into error code handling. Keep this
behavior by stashing the facility value found during our search and
checking for -1 if found.