The following file(s) added utf-8 encoding but never used. So we can
remove them at all.
test/functional/test_access_control.py
test/unit/common/middleware/crypto/test_keymaster.py
test/unit/obj/test_diskfile.py
Change-Id: I00adc968872ebe9f9c0619a4e393e048c7c1a91e