[SCSI] Revert "[SCSI] fix async probe regression"

This reverts commit 43a8d39d.

Commit 43a8d39d fixed the fact that wait_for_device_probe() was unable
to flush sd probe work.  Now that sd probe work is once again flushable
via wait_for_device_probe() this workaround is no longer needed.
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>

drivers/scsi/scsi_scan.c

@@ -147,7 +147,7 @@ int scsi_complete_async_scans(void)
 
 	do {
 		if (list_empty(&scanning_hosts))
-			goto out;
+			return 0;
 		/* If we can't get memory immediately, that's OK.  Just
 		 * sleep a little.  Even if we never get memory, the async
 		 * scans will finish eventually.
@@ -179,11 +179,8 @@ int scsi_complete_async_scans(void)
 	}
  done:
 	spin_unlock(&async_scan_lock);
-	kfree(data);
-
- out:
-	async_synchronize_full_domain(&scsi_sd_probe_domain);
 
+	kfree(data);
 	return 0;
 }