pallet nis: remove benchmarking hack (#13759)

* pallet nis: remove benchmark hack

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* NearestPrefDown -> Down

Tested on the kitchensink and in case that
n = 10000000000000000 and d = 12000100600000000000000 it rounds the
Perquintill up (correctly) since 833326347280+47318160/60000503 should round up.
That triggers the path 'amount <= on_hold' in L736.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/frame/nis/src/benchmarking.rs

@@ -164,9 +164,6 @@ benchmarks! {
 		Nis::<T>::place_bid(RawOrigin::Signed(caller.clone()).into(), bid, 1)?;
 		Nis::<T>::process_queues(Perquintill::one(), 1, 2, &mut WeightCounter::unlimited());
 		frame_system::Pallet::<T>::set_block_number(Receipts::<T>::get(0).unwrap().expiry);
-		// FIXME: Ensure that the pallet has enough funding. This should already be the case, but
-		// a rounding error can cause it to fail.
-		T::Currency::set_balance(&Nis::<T>::account_id(), BalanceOf::<T>::max_value() / 10u32.into());
 	}: _(RawOrigin::Signed(caller.clone()), 0, None)
 	verify {
 		assert!(Receipts::<T>::get(0).is_none());
@@ -185,9 +182,6 @@ benchmarks! {
 		Nis::<T>::process_queues(Perquintill::one(), 1, 2, &mut WeightCounter::unlimited());
 		frame_system::Pallet::<T>::set_block_number(Receipts::<T>::get(0).unwrap().expiry);
 		Nis::<T>::communify(RawOrigin::Signed(caller.clone()).into(), 0)?;
-		// FIXME: Ensure that the pallet has enough funding. This should already be the case, but
-		// a rounding error can cause it to fail.
-		T::Currency::set_balance(&Nis::<T>::account_id(), BalanceOf::<T>::max_value() / 10u32.into());
 	}: _(RawOrigin::Signed(caller.clone()), 0)
 	verify {
 		assert!(Receipts::<T>::get(0).is_none());

substrate/frame/nis/src/lib.rs

@@ -1139,9 +1139,8 @@ pub mod pallet {
 			// Now to activate the bid...
 			let n = amount;
 			let d = issuance.effective;
-			let proportion =
-				Perquintill::from_rational_with_rounding(n, d, Rounding::NearestPrefDown)
-					.defensive_unwrap_or_default();
+			let proportion = Perquintill::from_rational_with_rounding(n, d, Rounding::Down)
+				.defensive_unwrap_or_default();
 			let who = bid.who;
 			let index = summary.index;
 			summary.proportion_owed.defensive_saturating_accrue(proportion);