bcache: update comment for bch_data_insert

commit 220bb38c ("bcache: Break up struct search") introduced
changes to struct search and s->iop. bypass/bio are fields of struct
data_insert_op now. Update the comment.
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/request.c

@@ -311,11 +311,11 @@ static void bch_data_insert_start(struct closure *cl)
  * data is written it calls bch_journal, and after the keys have been added to
  * the next journal write they're inserted into the btree.
  *
- * It inserts the data in s->cache_bio; bi_sector is used for the key offset,
+ * It inserts the data in op->bio; bi_sector is used for the key offset,
  * and op->inode is used for the key inode.
  *
- * If s->bypass is true, instead of inserting the data it invalidates the
- * region of the cache represented by s->cache_bio and op->inode.
+ * If op->bypass is true, instead of inserting the data it invalidates the
+ * region of the cache represented by op->bio and op->inode.
  */
 void bch_data_insert(struct closure *cl)
 {