bio: fix argument of __bio_add_page() for max_sectors > 0xffff

The data type of max_sectors and max_hw_sectors in queue settings are
unsigned int.  But these values are passed to __bio_add_page() as an
argument whose data type is unsigned short.  In the worst case such as
max_sectors is 0x10000, bio_add_page() can't add a page and IOs can't
proceed.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/bio.c

@@ -601,7 +601,7 @@ EXPORT_SYMBOL(bio_get_nr_vecs);
 
 static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 			  *page, unsigned int len, unsigned int offset,
-			  unsigned short max_sectors)
+			  unsigned int max_sectors)
 {
 	int retried_segments = 0;
 	struct bio_vec *bvec;