xfs: use bio op accessors

Separate the op from the rq_flag_bits and have xfs
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 0cd1603..87d2b21 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -438,10 +438,8 @@
 
 	ioend->io_bio->bi_private = ioend;
 	ioend->io_bio->bi_end_io = xfs_end_bio;
-	if (wbc->sync_mode == WB_SYNC_ALL)
-		ioend->io_bio->bi_rw = WRITE_SYNC;
-	else
-		ioend->io_bio->bi_rw = WRITE;
+	bio_set_op_attrs(ioend->io_bio, REQ_OP_WRITE,
+			 (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0);
 	/*
 	 * If we are failing the IO now, just mark the ioend with an
 	 * error and finish it. This will run IO completion immediately
@@ -512,10 +510,8 @@
 
 	bio_chain(ioend->io_bio, new);
 	bio_get(ioend->io_bio);		/* for xfs_destroy_ioend */
-	if (wbc->sync_mode == WB_SYNC_ALL)
-		ioend->io_bio->bi_rw = WRITE_SYNC;
-	else
-		ioend->io_bio->bi_rw = WRITE;
+	bio_set_op_attrs(ioend->io_bio, REQ_OP_WRITE,
+			  (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0);
 	submit_bio(ioend->io_bio);
 	ioend->io_bio = new;
 }