channeldb: Fixes the count of payments returned by QueryPayments

QueryPayments function was changed to return the toyal num of payments
considering the date start and date end restrictions existing on the query

channeldb/payments.go

@@ -597,28 +597,7 @@ func (d *DB) QueryPayments(query PaymentsQuery) (PaymentsResponse, error) {
 		// literally have to traverse the cursor linearly, which can
 		// take quite a while. So it's an optional query parameter.
 		if query.CountTotal {
-			var (
-				totalPayments uint64
-				err           error
-			)
-			countFn := func(_, _ []byte) error {
-				totalPayments++
-
-				return nil
-			}
-
-			// In non-boltdb database backends, there's a faster
-			// ForAll query that allows for batch fetching items.
-			if fastBucket, ok := indexes.(kvdb.ExtendedRBucket); ok {
-				err = fastBucket.ForAll(countFn)
-			} else {
-				err = indexes.ForEach(countFn)
-			}
-			if err != nil {
-				return fmt.Errorf("error counting payments: %w",
-					err)
-			}
-
+			totalPayments := uint64(len(resp.Payments))
 			resp.TotalCount = totalPayments
 		}