Merge remote-tracking branch 'remotes/berrange/tags/qcrypto-next-pull-request' into staging

Refactoring of LUKS support to facilitate keyslot updates

No current functional change is expected with this series.

# gpg: Signature made Fri 27 Sep 2019 10:58:54 BST
# gpg:                using RSA key DAF3A6FDB26B62912D0E8E3FBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>" [full]
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>" [full]
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/qcrypto-next-pull-request:
  qcrypto-luks: more rigorous header checking
  qcrypto-luks: simplify the math used for keyslot locations
  qcrypto-luks: extract store key function
  qcrypto-luks: extract check and parse header
  qcrypto-luks: extract store and load header
  qcrypto-luks: purge unused error codes from open callback
  qcrypto-luks: use the parsed encryption settings in QCryptoBlockLUKS
  qcrypto-luks: pass keyslot index rather that pointer to the keyslot
  qcrypto-luks: simplify masterkey and masterkey length
  qcrypto-luks: don't overwrite cipher_mode in header
  qcrypto-luks: rename some fields in QCryptoBlockLUKSHeader

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