Since all direct bdev_io types have the same layout,
there is no need to keep them differentiated.
Change-Id: If8bb85e43c9922c0ebfc39837e3a45006e508b56
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/377686
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>