coccinnelle: Remove ptr_ret script

The ptr_ret script script addresses a number of situations where we end up
testing an error pointer, and if it's an error returning it, or return 0
otherwise to transform it into a PTR_ERR_OR_ZERO call.

So it will convert a block like this:

if (IS_ERR(err))
    return PTR_ERR(err);

return 0;

into

return PTR_ERR_OR_ZERO(err);

While this is technically correct, it has a number of drawbacks. First, it
merges the error and success path, which will make it harder for a reviewer
or reader to grasp.

It's also more difficult to extend if we were to add some code between the
error check and the function return, making the author essentially revert
that patch before adding new lines, while it would have been a trivial
addition otherwise for the rewiever.

Therefore, since that script is only about cosmetic in the first place,
let's remove it since it's not worth it.

Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>