routing: remove redundant fee limit check in newRoute

This check was a left over from when the fee limit wasn't checked yet in
the path finding algorithm.

routing/payment_session.go

@@ -163,8 +163,7 @@ func (p *paymentSession) RequestRoute(payment *LightningPayment,
 	// a route by applying the time-lock and fee requirements.
 	sourceVertex := Vertex(p.mc.selfNode.PubKeyBytes)
 	route, err := newRoute(
-		payment.Amount, payment.FeeLimit, sourceVertex, path, height,
-		finalCltvDelta,
+		payment.Amount, sourceVertex, path, height, finalCltvDelta,
 	)
 	if err != nil {
 		// TODO(roasbeef): return which edge/vertex didn't work