ZFS: Always refuse receving non-resume stream when resume state exists

This fixes a hole in the situation where the resume state is left from
receiving a new dataset and, so, the state is set on the dataset itself
(as opposed to %recv child).

Additionally, distinguish incremental and resume streams in error
messages.

This was also committed to ZoL:
zfsonlinux/zfs@ebeb6f23bf7e8fe6732a05267ed1cab4c38d3b23

MFC after: 2 weeks
Sponsored by: CyberSecure