offences: make fn slash_fraction non-static (#11956)

* offences: make fn slash_fraction non-static

* Bastifmt (inline variable)

substrate/frame/offences/benchmarking/src/lib.rs

@@ -288,15 +288,13 @@ benchmarks! {
 		let (offenders, raw_offenders) = make_offenders_im_online::<T>(o, n)?;
 		let keys =  ImOnline::<T>::keys();
 		let validator_set_count = keys.len() as u32;
-
-		let slash_fraction = UnresponsivenessOffence::<T::AccountId>::slash_fraction(
-			offenders.len() as u32, validator_set_count,
-		);
+		let offenders_count = offenders.len() as u32;
 		let offence = UnresponsivenessOffence {
 			session_index: 0,
 			validator_set_count,
 			offenders,
 		};
+		let slash_fraction = offence.slash_fraction(offenders_count);
 		assert_eq!(System::<T>::event_count(), 0);
 	}: {
 		let _ = <T as ImOnlineConfig>::ReportUnresponsiveness::report_offence(

substrate/frame/offences/src/lib.rs

@@ -120,7 +120,6 @@ where
 	fn report_offence(reporters: Vec<T::AccountId>, offence: O) -> Result<(), OffenceError> {
 		let offenders = offence.offenders();
 		let time_slot = offence.time_slot();
-		let validator_set_count = offence.validator_set_count();
 
 		// Go through all offenders in the offence report and find all offenders that were spotted
 		// in unique reports.
@@ -134,7 +133,7 @@ where
 		let offenders_count = concurrent_offenders.len() as u32;
 
 		// The amount new offenders are slashed
-		let new_fraction = O::slash_fraction(offenders_count, validator_set_count);
+		let new_fraction = offence.slash_fraction(offenders_count);
 
 		let slash_perbill: Vec<_> = (0..concurrent_offenders.len()).map(|_| new_fraction).collect();
 

substrate/frame/offences/src/mock.rs

@@ -168,8 +168,8 @@ impl<T: Clone> offence::Offence<T> for Offence<T> {
 		1
 	}
 
-	fn slash_fraction(offenders_count: u32, validator_set_count: u32) -> Perbill {
-		Perbill::from_percent(5 + offenders_count * 100 / validator_set_count)
+	fn slash_fraction(&self, offenders_count: u32) -> Perbill {
+		Perbill::from_percent(5 + offenders_count * 100 / self.validator_set_count)
 	}
 }