Can I safely perform a manual clean up of a few mountpints left behind by LU?

Hello,
After a recent update with LU I've noticed what it seems to be temporary mountpoints "left behind".

# zfs list -t fs
NAME                         USED  AVAIL  REFER  MOUNTPOINT
rpool                       11.2G   123G   106K  /rpool
rpool/ROOT                  8.17G   123G    31K  legacy
rpool/ROOT/20120817-v1       104M   123G  4.59G  /tmp/.liveupgrade.330.505/lu_zone_update.505
rpool/ROOT/20120817-v1/var  16.6M   123G  3.09G  /tmp/.liveupgrade.330.505/lu_zone_update.505/var
rpool/ROOT/20120828-v1      8.07G   123G  4.59G  /
rpool/ROOT/20120828-v1/var  3.27G   123G  3.24G  /var
...
rpool/export                 102K   123G    32K  /export
rpool/export/home           69.5K   123G    32K  /export/home
...

My question is:
Should I ignore them or must I manually adjust them with