bio.h: fix kernel-doc warnings

Fix all kernel-doc warnings in <linux/bio.h>:

include/linux/bio.h:136: warning: Function parameter or member 'nbytes' not described in 'bio_advance'
include/linux/bio.h:136: warning: Excess function parameter 'bytes' description in 'bio_advance'
include/linux/bio.h:391: warning: No description found for return value of 'bio_next_split'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Link: https://lore.kernel.org/r/20211222211532.24060-1-rdunlap@infradead.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/bio.h

@@ -124,7 +124,7 @@ void __bio_advance(struct bio *, unsigned bytes);
 /**
  * bio_advance - increment/complete a bio by some number of bytes
  * @bio:	bio to advance
- * @bytes:	number of bytes to complete
+ * @nbytes:	number of bytes to complete
  *
  * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
  * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
@@ -332,7 +332,7 @@ extern struct bio *bio_split(struct bio *bio, int sectors,
  * @gfp:	gfp mask
  * @bs:		bio set to allocate from
  *
- * Returns a bio representing the next @sectors of @bio - if the bio is smaller
+ * Return: a bio representing the next @sectors of @bio - if the bio is smaller
  * than @sectors, returns the original bio unchanged.
  */
 static inline struct bio *bio_next_split(struct bio *bio, int sectors,