Fix the ENGINE_finish/ENGINE_free mixup
Fix the ENGINE_finish/ENGINE_free mixup

The tests were calling finish when it meant free. This caused tests to
segmentation fault next time the ENGINE was looked up in the dynamic
engine list.

Bug: 14994037
Change-Id: If7379fee26f7e79fa0b43104ac9d13b4ffb62ba8

google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt