Don't update the `prev_owner` when granting sealer/unsealers
`membrane_grant_single` would skip the grant if someone tried to grant a sealer unsealer (since sealer/unsealers are not supposed to ever be wrapped). However, `cn_membrane_grant` would still update the previous owner to be the membrane's secret cspace despite the fact that the grant never occurred so the sealer/unsealer did not exist in that c-space. This commit adds a new error code ESKIPPED that can be returned to signal that an operation was skipped, so tracking data structures don't necessarily need to be updated.
Showing with 26 additions and 14 deletions