02ccb0f791
If a bdev doesn't need to be polled, allow it to specify NULL for the check_io function pointer to indicate that no poller needs to be registered. This will be useful for virtual blockdevs that don't have any associated hardware to poll. Change-Id: I0ef8f848587b0c200296805ccc710340dde683b5 Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>