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

- Aneesh no longer listed in MAINTAINERS,
- deprecation of the handle backend,
- improved error reporting, especially when the local backend fails to
  open the VirtFS root,
- virtio-9p-test to behave more like a real virtio guest driver: set
  DRIVER_OK when ready to use the device and process the used ring
  for completed requests,
- cosmetic fixes (mostly coding style related).

# gpg: Signature made Mon 08 Jan 2018 10:19:18 GMT
# gpg:                using RSA key 0x71D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg:                 aka "Gregory Kurz <gregory.kurz@free.fr>"
# gpg:                 aka "[jpeg image of size 3330]"
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3  4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/for-upstream:
  MAINTAINERS: Drop Aneesh as 9pfs maintainer
  9pfs: deprecate handle backend
  fsdev: improve error handling of backend init
  fsdev: improve error handling of backend opts parsing
  tests: virtio-9p: set DRIVER_OK before using the device
  tests: virtio-9p: fix ISR dependence
  9pfs: make pdu_marshal() and pdu_unmarshal() static functions
  9pfs: fix error path in pdu_submit()
  9pfs: fix type in *_parse_opts declarations
  9pfs: handle: fix type definition
  9pfs: fix some type definitions
  fsdev: fix some type definitions
  9pfs: fix XattrOperations typedef
  virtio-9p: move unrealize/realize after virtio_9p_transport definition

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