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.
Reviewed-by: Matt Ahrens <matt@delphix.com> Reviewed-by: Tom Caputi <tcaputi@datto.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Closes #9252