btrfs: make btrfs_lookup_ordered_extent take btrfs_inode

It doesn't use the generic vfs inode for anything use btrfs_inode
directly.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 690549d..bd69367 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4558,7 +4558,7 @@ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
 	lock_extent_bits(io_tree, block_start, block_end, &cached_state);
 	set_page_extent_mapped(page);
 
-	ordered = btrfs_lookup_ordered_extent(inode, block_start);
+	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), block_start);
 	if (ordered) {
 		unlock_extent_cached(io_tree, block_start, block_end,
 				     &cached_state);