Illumos 5348 - zio_checksum_error() only fills in info if ECKSUM

5348 zio_checksum_error() only fills in info if ECKSUM
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Approved by: Dan McDonald <danmcd@omniti.com>

References:

https://www.illumos.org/issues/5348
https://github.com/illumos/illumos-gate/commit/373dc1cf

Ported-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3372