vfs: Improve the bio_add_page() and bio_add_pc_page() descriptions

The descriptions of bio_add_page() and bio_add_pc_page() are slightly
inconsistent; improve them.
Signed-off-by: Andreas Gruenbacher <agruen@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/bio.c

@@ -638,10 +638,11 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
  *	@offset: vec entry offset
  *
  *	Attempt to add a page to the bio_vec maplist. This can fail for a
- *	number of reasons, such as the bio being full or target block
- *	device limitations. The target block device must allow bio's
- *      smaller than PAGE_SIZE, so it is always possible to add a single
- *      page to an empty bio. This should only be used by REQ_PC bios.
+ *	number of reasons, such as the bio being full or target block device
+ *	limitations. The target block device must allow bio's up to PAGE_SIZE,
+ *	so it is always possible to add a single page to an empty bio.
+ *
+ *	This should only be used by REQ_PC bios.
  */
 int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page,
 		    unsigned int len, unsigned int offset)
@@ -659,10 +660,9 @@ EXPORT_SYMBOL(bio_add_pc_page);
  *	@offset: vec entry offset
  *
  *	Attempt to add a page to the bio_vec maplist. This can fail for a
- *	number of reasons, such as the bio being full or target block
- *	device limitations. The target block device must allow bio's
- *      smaller than PAGE_SIZE, so it is always possible to add a single
- *      page to an empty bio.
+ *	number of reasons, such as the bio being full or target block device
+ *	limitations. The target block device must allow bio's up to PAGE_SIZE,
+ *	so it is always possible to add a single page to an empty bio.
  */
 int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
 		 unsigned int offset)