drm: cleanup DRM_DEBUG() parameters

As DRM_DEBUG macro already prints out the __FUNCTION__ string (see
drivers/char/drm/drmP.h), it is not worth doing this again. At some
other places the ending "\n" was added.

airlied:- I cleaned up a few that this patch missed also

Signed-off-by: Dave Airlie <airlied@linux.ie>