message: Match additive notation with variable name
diff: @@ -37,11 +37,11 @@ impl<E: JubjubEngine> PrivateKey<E> {
  let r = h_star::<E>(&t[..], msg);
  // R = r . G
  - let g_r = params
  + let r_g = params
  .generator(FixedGenerators::SpendingKeyGenerator)
  .mul(r, params);
  let mut rbar = [0u8; 32];
  - g_r.write(&mut rbar[..])
  + r_g.write(&mut rbar[..])
  .expect("Jubjub points should serialize to 32 bytes");
  // S = r + H*(Rbar || M) . sk
  @@ -49,7 +49,7 @@ impl<E: JubjubEngine> PrivateKey<E> {
  s.mul_assign(&self.0);
  s.add_assign(&r);
  - Signature { r: g_r.into(), s }
  + Signature { r: r_g.into(), s }
  }
  }
  