ota: OtaAlgo{Crypt,Auth}: fix algo_auth vs algo_crypt
* OtaAlgoCrypt.from_keyset() searches by `otak.algo_crypt`
but the error message prints `otak.algo_auth`. Should be
`otak.algo_crypt` instead.
* OtaAlgoAuth.__init__() checks `algo_auth` but the error message
prints `algo_crypt`. Should be `otak.algo_auth` instead.
Change-Id: Ia636fffaeadc68e3f6d5b65d477e753834c95895
