Duplicate mention of raw option in zfs man8

[JMoVS]

https://github.com/openzfsonosx/zfs/blob/45a20a87262e3f949cd11fb7c4ed9f65742e2ff8/man/man8/zfs.8#L3122

This is the second mention, we only need one mention of the raw send option. When considering which one to remove, we should probably make sure to make it similar to ZOL.