Remove unused variables:
* tree from csum_dirty_buffer,
* tree from btree_readpage_end_io_hook,
* tree from btree_writepages,
* bytenr from btrfs_create_tree,
* fs_info from end_workqueue_fn.
Signed-off-by: NValentina Giusti <valentina.giusti@microon.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>