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/ext4/page-io.c b/fs/ext4/page-io.c
index 0094923..e0b3b54 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -340,7 +340,7 @@ void ext4_io_submit(struct ext4_io_submit *io)
 
 	if (bio) {
 		int io_op_flags = io->io_wbc->sync_mode == WB_SYNC_ALL ?
-				  WRITE_SYNC : 0;
+				  REQ_SYNC : 0;
 		bio_set_op_attrs(io->io_bio, REQ_OP_WRITE, io_op_flags);
 		submit_bio(io->io_bio);
 	}