Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Fri 09 Jun 2017 12:47:31 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: fix external snapshot abort permission error
  block/qcow.c: Fix memory leak in qcow_create()
  qemu-iotests: Test automatic commit job cancel on hot unplug
  commit: Fix use after free in completion
  qemu-iotests: Block migration test
  migration/block: Clean up BBs in block_save_complete()
  migration: Inactivate images after .save_live_complete_precopy()
  block: Fix anonymous BBs in blk_root_inactivate()

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