tests/12-edit-chroot: Fix references to 'enter-chroot' that should be 'edit-chroot'

Test '12-edit-chroot' had entries added for the '-a' ALLCHROOTS
and '-l' LISTDETAILS options. Some of these tests mistakenly used
the script 'enter-chroot' instead of 'edit-chroot'.
tests/12-edit-chroot: Add tee /dev/stderr to debug #1106