daemon: move variables into struct daemon_state

The fact that most of the daemon's state is stored on the stack
of the main() makes it hard to split the logic smaller chunks.
Which in turn leads to huge main func that does a a lot of things.
struct log_params existed because some variables need to be passed
into other functions together.

This change renames struct log_params into daemon_state
and moves the rest of the variables into it. This is a necessary
preparation step for further refactroing.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/687