nbd: Minor style and typo fixes

Touch up a comment with the wrong type name, and an over-long line,
both noticed while working on upcoming patches.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20240807174943.771624-10-eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2 files changed