Test that if a key to be purged is in the keyring, it does not
prevent the keymgr from running. Normally a key that is in the keyring
should be available again on the next run, but that is not true for
a key that can be purged.
In addition, fix some wait_for_log calls, by adding the missing
'|| ret=1' parts.
(cherry picked from commit a2317425bc)
80d5b3877a