Change return value of ecdsa_sign_digest
Change return value of ecdsa_sign_digest

Error codes were not being propagated, always returned as 0.
trezor/trezor-crypto,01BTC10/trezor-crypto,trezor/trezor-crypto,jhoenicke/trezor-crypto,runn1ng/trezor-crypto,romanz/trezor-crypto,trezor/trezor-crypto,romanz/trezor-crypto,runn1ng/trezor-crypto,jhoenicke/trezor-crypto,romanz/trezor-crypto,runn1ng/trezor-crypto,jhoenicke/trezor-crypto,jhoenicke/trezor-crypto,trezor/trezor-crypto,trezor/trezor-crypto,01BTC10/trezor-crypto,01BTC10/trezor-crypto,romanz/trezor-crypto,jhoenicke/trezor-crypto,runn1ng/trezor-crypto,romanz/trezor-crypto,runn1ng/trezor-crypto