drm/print: clean up RATELIMITED macros

Drop a few indirections, making the code simpler.
This also drops a RATELIMITED variant that is not in use.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214175919.GA14492@ravnborg.org