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/block/blk-map.c b/block/blk-map.c
index b9f88b7..61733a6 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -224,7 +224,7 @@
 		return PTR_ERR(bio);
 
 	if (!reading)
-		bio->bi_rw |= REQ_WRITE;
+		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 
 	if (do_copy)
 		rq->cmd_flags |= REQ_COPY_USER;