btrfs: remove stale comments about fs_mutex

The fs_mutex has been killed in 2008, a213501153 ("Btrfs: Replace
the big fs_mutex with a collection of other locks"), still remembered in
some comments.

We don't have any extra needs for locking in the ACL handlers.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2018-03-27 20:08:28 +02:00
commit e7ab0af6c3