btrfs: remove obsolete comment in btrfs_clean_one_deleted_snapshot
btrfs: remove obsolete comment in btrfs_clean_one_deleted_snapshot

The comment applied when there was a BUG_ON.

Signed-off-by: David Sterba <a2ce9d316ca04d17b520237d2846a218b8284e52@suse.cz>
Signed-off-by: Chris Mason <e2e8c5702d8ed5f565988a1cf5bb35c9ce199e5e@fb.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs