Fix bug in OchSignal toString

Change-Id: Ice411f3ea2ed3b3a89069993752427f4298d4134
diff --git a/core/api/src/main/java/org/onosproject/net/OchSignal.java b/core/api/src/main/java/org/onosproject/net/OchSignal.java
index 65f430c..93ec6f8 100644
--- a/core/api/src/main/java/org/onosproject/net/OchSignal.java
+++ b/core/api/src/main/java/org/onosproject/net/OchSignal.java
@@ -253,8 +253,7 @@
         return String.format("%s{%+d×%.2fGHz ± %.2fGHz}",
                 this.getClass().getSimpleName(),
                 spacingMultiplier,
-                (double) slotGranularity * channelSpacing.frequency().asHz()
-                        / Frequency.ofGHz(1).asHz(),
+                (double) channelSpacing.frequency().asHz() / Frequency.ofGHz(1).asHz(),
                 (double) slotGranularity * ChannelSpacing.CHL_12P5GHZ.frequency().asHz()
                         / Frequency.ofGHz(1).asHz() / 2.0);
     }