block: fold bio_cur_bytes into blk_rq_cur_bytes

Fold bio_cur_bytes into the only caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012161804.991559-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/bio.h

@@ -69,14 +69,6 @@ static inline bool bio_no_advance_iter(const struct bio *bio)
 	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
 }
 
-static inline unsigned int bio_cur_bytes(struct bio *bio)
-{
-	if (bio_has_data(bio))
-		return bio_iovec(bio).bv_len;
-	else /* dataless requests such as discard */
-		return bio->bi_iter.bi_size;
-}
-
 static inline void *bio_data(struct bio *bio)
 {
 	if (bio_has_data(bio))

include/linux/blk-mq.h

@@ -927,7 +927,11 @@ static inline unsigned int blk_rq_bytes(const struct request *rq)
 
 static inline int blk_rq_cur_bytes(const struct request *rq)
 {
-	return rq->bio ? bio_cur_bytes(rq->bio) : 0;
+	if (!rq->bio)
+		return 0;
+	if (!bio_has_data(rq->bio))	/* dataless requests such as discard */
+		return rq->bio->bi_iter.bi_size;
+	return bio_iovec(rq->bio).bv_len;
 }
 
 unsigned int blk_rq_err_bytes(const struct request *rq);