btrfs: Remove unused extent_root var from caching_thread

Added by b4570aa994 ("btrfs: fix compiling with CONFIG_BTRFS_DEBUG
enabled.") and obsoleted by 2ff7e61e0d ("btrfs: take an fs_info
directly when the root is not used otherwise").

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov 2018-03-15 14:36:28 +02:00 • committed by David Sterba
commit 101d2dc0b2