Make zstreamdump -v more greppable

Make zstreamdump -v more greppable

Currently, the verbose output of zstreamdump includes new line
characters within some individual records. Presumably, this was
originally done to keep the output from getting too wide to fit
on a terminal. However, since new flags and struct members have
been added, these rules have not been maintained consistently. In
addition, these newlines can make it hard to grep the output in
some scenarios. This patch simply removes these newlines, making
the output easier to grep and removing the inconsistency.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Allan Jude <allanjude@freebsd.org>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8493