mfii_exec_done clears ccb_cookie, so mfii_exec should test that, not ccb_done.
mfii_exec_done clears ccb_cookie, so mfii_exec should test that, not
ccb_done.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars