For consoles like netconsole and blockconsole the loglevel filtering
really doesn't make any sense. If a line gets printed at all, please
send it down to that console, no questions asked.
For vga_con, it is a completely different matter, as the user sitting in
front of his console could get spammed by messages while trying to login
or similar. So ignore_loglevel doesn't work as a one-size-fits-all
approach. Add a per-console flag instead so that netconsole and
blockconsole can opt-in.