AcquireCredentialsHandle with an unknown package should return SecurityPackageNotFound

[jborean93]

Currently when calling AcquireCredentialsHandle with an invalid package name it returns SEC_E_INVALID_PARAMETER / InvalidParameter. When using SSPI actual the return value is actually SEC_E_SECPKG_NOT_FOUND / SecurityPackageNotFound. It would be great if they could align in behaviour here.