Relying on the simplified version of the synchronous support for RAW
disk files, the new fixed_vhd_sync module in the block_util crate
introduces the synchronous support for fixed VHD disk files.
With this patch, the fixed VHD support is complete as it is implemented
in both synchronous and asynchronous versions.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
