By failing to set the errno, we'd continue on to trying to set up the
RCL, and then oops on trying to dereference the tile_bo that binning
validation should have set up.
Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NEric Anholt <eric@anholt.net>
Fixes: d5b1a78a ("drm/vc4: Add support for drawing 3D frames.")