drm: update todo.rst

- debugfs cleanup has moved forward thanks to the cleanup Wambui has
  done
Acked-by: NMelissa Wen <melissa.srw@gmail.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Wambui Karuga <wambui.karugax@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Melissa Wen <melissa.srw@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200929150333.3441576-1-daniel.vetter@ffwll.ch

Documentation/gpu/todo.rst

@@ -515,9 +515,6 @@ There's a bunch of issues with it:
   this (together with the drm_minor->drm_device move) would allow us to remove
   debugfs_init.
 
-- Drop the return code and error checking from all debugfs functions. Greg KH is
-  working on this already.
-
 Contact: Daniel Vetter
 
 Level: Intermediate