Merge remote-tracking branch 'remotes/berrange/tags/pull-io-next-2016-01-20-1' into...

Merge remote-tracking branch 'remotes/berrange/tags/pull-io-next-2016-01-20-1' into staging

I/O channels fixes 2016/01/20 v1

# gpg: Signature made Wed 20 Jan 2016 11:31:47 GMT using RSA key ID 15104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"

* remotes/berrange/tags/pull-io-next-2016-01-20-1:
  io: use memset instead of { 0 } for initializing array
  io: fix description of @errp parameter initialization
  io: some fixes to handling of /dev/null when running commands
  io: increment counter when killing off subcommand
  io: fix sign of errno value passed to error report

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>