message: Simplify signature deserialization
diff: @@ -17,7 +17,7 @@ pub fn ed25519_verify(
  public_key_bytes: &[u8],
  ) -> VmResult<()> {
  // Deserialize
  - let res: Result<ed25519::Signature, ed25519::Error> = signature_bytes.try_into();
  + let res = ed25519::Signature::try_from(signature_bytes);
  let signature = res.map_err(|err| VmError::crypto_err(err.to_string()))?;
  ed25519::VerificationKey::try_from(public_key_bytes)
  