message: fix(writer): Set flags manually to avoid verifying cache
  We change from using `rs+` to a composition of read/write,
  exlusive, sync & direct i/o flags, in order to avoid reading
  stale data from the cache during verification.
  Change-Type: patch
  Changelog-Entry: Fix verification step reading from the cache
diff: @@ -75,7 +75,15 @@ exports.writeImage = (imagePath, drive, options, onProgress) => {
  }).then(() => {
  return diskpart.clean(drive.device)
  }).then(() => {
  - return fs.openAsync(drive.raw, 'rs+')
  + /* eslint-disable no-bitwise */
  + const flags = fs.constants.O_RDWR |
  + fs.constants.O_EXCL |
  + fs.constants.O_NONBLOCK |
  + fs.constants.O_SYNC |
  + fs.constants.O_DIRECT
  + /* eslint-enable no-bitwise */
  +
  + return fs.openAsync(drive.raw, flags)
  }).then((driveFileDescriptor) => {
  return imageStream.getFromFilePath(imagePath).then((image) => {
  if (!constraints.isDriveLargeEnough(drive, image)) {
  