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

Block layer patches:

- iotests fixes

# gpg: Signature made Fri 12 Apr 2019 17:04:09 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotest: Fix 241 to run in generic directory
  iotests: Let 245 pass on tmpfs

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