rate: remove redundant return statements

Change-Id: Ic8a2d466d570ec503c75c45d9a5a8741eacacd6f
Reviewed-on: https://go-review.googlesource.com/c/time/+/325610
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/rate/rate.go b/rate/rate.go
index a98fe77..c0f7a57 100644
--- a/rate/rate.go
+++ b/rate/rate.go
@@ -145,7 +145,6 @@
 // Cancel is shorthand for CancelAt(time.Now()).
 func (r *Reservation) Cancel() {
 	r.CancelAt(time.Now())
-	return
 }
 
 // CancelAt indicates that the reservation holder will not perform the reserved action
@@ -186,8 +185,6 @@
 			r.lim.lastEvent = prevEvent
 		}
 	}
-
-	return
 }
 
 // Reserve is shorthand for ReserveN(time.Now(), 1).