fuse: use DIV_ROUND_UP helper macro for calculations

Replace open coded divisor calculations with the DIV_ROUND_UP kernel macro
for better readability.
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/fuse/file.c

@@ -1405,7 +1405,7 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
 		nbytes += ret;
 
 		ret += start;
-		npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
+		npages = DIV_ROUND_UP(ret, PAGE_SIZE);
 
 		ap->descs[ap->num_pages].offset = start;
 		fuse_page_descs_length_init(ap->descs, ap->num_pages, npages);