Now that scsi registers its async scan work with the async subsystem,
wait_for_device_probe() is sufficient for ensuring all scanning is
complete.

[jejb: fix merge problems with eea03c20 Make wait_for_device_probe() also do scsi_complete_async_scans()]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>