[SCSI] Remove host template ordered_flush variable

After the recent overhaul of the block layer the variable
"ordered_flush" is no longer used.

Signed-off-by: Tetsuo Takata <takatatt@intellilink.co.jp>
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 467274a..8279929 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -554,7 +554,6 @@
 	/*
 	 * ordered write support
 	 */
-	unsigned ordered_flush:1;
 	unsigned ordered_tag:1;
 
 	/*