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

Block layer patches:

- fdc: Fix inserting read-only media in empty drive

# gpg: Signature made Tue 30 Jul 2019 16:32:14 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <[email protected]>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests/118: Test inserting a read-only medium
  fdc: Fix inserting read-only media in empty drive

Signed-off-by: Peter Maydell <[email protected]>