Merge remote-tracking branch 'remotes/berrange/tags/pull-qio-2017-01-26-1' into staging

Merge io/ 2017/01/26

# gpg: Signature made Thu 26 Jan 2017 10:26:48 GMT
# gpg:                using RSA key 0xBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/pull-qio-2017-01-26-1:
  io: fix possible double free of task error object

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