block, fs, mm, drivers: use bio set/get op accessors

This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_op

These should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index d06c62e..9393bc7 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1074,7 +1074,7 @@
 			BUG();
 
 		atomic_inc(&pkt->io_wait);
-		bio->bi_rw = READ;
+		bio_set_op_attrs(bio, REQ_OP_READ, 0);
 		pkt_queue_bio(pd, bio);
 		frames_read++;
 	}
@@ -1336,7 +1336,7 @@
 
 	/* Start the write request */
 	atomic_set(&pkt->io_wait, 1);
-	pkt->w_bio->bi_rw = WRITE;
+	bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
 	pkt_queue_bio(pd, pkt->w_bio);
 }