dax: drop size parameter to ->direct_access()

None of the implementations currently use it.  The common
bdev_direct_access() entry point handles all the size checks before
calling ->direct_access().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 2345a98..3831e56 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -462,7 +462,7 @@
 	sector += get_start_sect(bdev);
 	if (sector % (PAGE_SIZE / 512))
 		return -EINVAL;
-	avail = ops->direct_access(bdev, sector, addr, pfn, size);
+	avail = ops->direct_access(bdev, sector, addr, pfn);
 	if (!avail)
 		return -ERANGE;
 	return min(avail, size);