sed-opal: Remove the ret variable from the function

The ret variable in the function has not yet been effective and can be
removed.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
Link: https://lore.kernel.org/r/20240306101444.1244-1-kunyu@nfschina.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>