ublk: sanity check add_dev input for underflow

Add additional checks that queue depth and number of queues are
non-zero.

Signed-off-by: Ronnie Sahlberg <rsahlberg@whamcloud.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250626022046.235018-1-ronniesahlberg@gmail.com


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