block,fs: use REQ_* flags directly

Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c8454a8..fe10afd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3485,9 +3485,9 @@ static int write_dev_supers(struct btrfs_device *device,
 		 * to go down lazy.
 		 */
 		if (i == 0)
-			ret = btrfsic_submit_bh(REQ_OP_WRITE, WRITE_FUA, bh);
+			ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_FUA, bh);
 		else
-			ret = btrfsic_submit_bh(REQ_OP_WRITE, WRITE_SYNC, bh);
+			ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
 		if (ret)
 			errors++;
 	}
@@ -3551,7 +3551,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
 
 	bio->bi_end_io = btrfs_end_empty_barrier;
 	bio->bi_bdev = device->bdev;
-	bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH);
+	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 	init_completion(&device->flush_wait);
 	bio->bi_private = &device->flush_wait;
 	device->flush_bio = bio;