Swap Vec<&RouteHop> parameters for slices

[TheBlueMatt]

In c353c3e, new scorer-updating methods were added to the Router object, however they were passed as a Vec of references. We use the list-of-references pattern to make bindings simpler (by not requiring allocations per entry), however there's no reason prefer to passing a Vec over a slice, given the Vec doesn't hold ownership of the objects anyway.

We also add a second commit which replaces an Option<&u64> with an Option<u64>.

[codecov-commenter]

Codecov Report

Base: 90.73% // Head: 90.71% // Decreases project coverage by -0.01% ⚠️

Coverage data is based on head (85eb1fd) compared to base (dc28f9b).
Patch coverage: 30.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1728      +/-   ##
==========================================
- Coverage   90.73%   90.71%   -0.02%     
==========================================
  Files          86       86              
  Lines       46675    46679       +4     
  Branches    46675    46679       +4     
==========================================
- Hits        42350    42345       -5     
- Misses       4325     4334       +9     

Impacted Files	Coverage Δ
lightning-invoice/src/utils.rs	94.85% <0.00%> (ø)
lightning-invoice/src/payment.rs	89.85% <40.90%> (-0.27%)	⬇️
lightning/src/ln/monitor_tests.rs	99.44% <0.00%> (-0.12%)	⬇️
lightning/src/ln/functional_tests.rs	96.99% <0.00%> (-0.08%)	⬇️
lightning/src/util/events.rs	38.40% <0.00%> (+0.26%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[tnull]

LGTM, mod above feedback.

[TheBlueMatt]

Dropped the excess ampersands and went ahead and squashed since its super trivial:

$ git diff-tree -U1 6d6b9cc4 85eb1fde
diff --git a/lightning-invoice/src/payment.rs b/lightning-invoice/src/payment.rs
index 5af6cb766..3b4fe7092 100644
--- a/lightning-invoice/src/payment.rs
+++ b/lightning-invoice/src/payment.rs
@@ -1847,3 +1847,3 @@ mod tests {
 		fn notify_payment_path_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-			self.scorer.lock().payment_path_failed(&path, short_channel_id);
+			self.scorer.lock().payment_path_failed(path, short_channel_id);
 		}
@@ -1851,3 +1851,3 @@ mod tests {
 		fn notify_payment_path_successful(&self, path: &[&RouteHop]) {
-			self.scorer.lock().payment_path_successful(&path);
+			self.scorer.lock().payment_path_successful(path);
 		}
@@ -1855,3 +1855,3 @@ mod tests {
 		fn notify_payment_probe_successful(&self, path: &[&RouteHop]) {
-			self.scorer.lock().probe_successful(&path);
+			self.scorer.lock().probe_successful(path);
 		}
@@ -1859,3 +1859,3 @@ mod tests {
 		fn notify_payment_probe_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-			self.scorer.lock().probe_failed(&path, short_channel_id);
+			self.scorer.lock().probe_failed(path, short_channel_id);
 		}
diff --git a/lightning-invoice/src/utils.rs b/lightning-invoice/src/utils.rs
index 8c96edbb0..5faecbfab 100644
--- a/lightning-invoice/src/utils.rs
+++ b/lightning-invoice/src/utils.rs
@@ -486,3 +486,3 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultR
 	fn notify_payment_path_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-		self.scorer.lock().payment_path_failed(&path, short_channel_id);
+		self.scorer.lock().payment_path_failed(path, short_channel_id);
 	}
@@ -490,3 +490,3 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultR
 	fn notify_payment_path_successful(&self, path: &[&RouteHop]) {
-		self.scorer.lock().payment_path_successful(&path);
+		self.scorer.lock().payment_path_successful(path);
 	}
@@ -494,3 +494,3 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultR
 	fn notify_payment_probe_successful(&self, path: &[&RouteHop]) {
-		self.scorer.lock().probe_successful(&path);
+		self.scorer.lock().probe_successful(path);
 	}
@@ -498,3 +498,3 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultR
 	fn notify_payment_probe_failed(&self, path: &[&RouteHop], short_channel_id: u64) {
-		self.scorer.lock().probe_failed(&path, short_channel_id);
+		self.scorer.lock().probe_failed(path, short_channel_id);
 	}