Merge tag 'block-pull-request' into staging

# gpg: Signature made Fri 12 May 2017 10:37:12 AM EDT
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* tag 'block-pull-request':
  aio: add missing aio_notify() to aio_enable_external()
  block: Simplify BDRV_BLOCK_RAW recursion
  coroutine: remove GThread implementation

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>