RP1210API.GetErrorMsg should fall back to translating the error message rather than translating GetErrorMsg's return code.

[dfieschko]

When a user calls GetErrorMsg, they want a translation of their error code. If RP1210_GetErrorMsg returns a code, we don't want to translate that instead of ErrorMessage, since that's confusing.

Instead of:

return translateErrorCode(ret_code)

We should have:

return translateErrorCode(ErrorCode)