remove useless variable

Change-Id: Iec4cfc709544644129bb8638e16db3c9a03bffc8
diff --git a/thread/framework/java/android/net/thread/ThreadNetworkController.java b/thread/framework/java/android/net/thread/ThreadNetworkController.java
index cb4e8de..3635e60 100644
--- a/thread/framework/java/android/net/thread/ThreadNetworkController.java
+++ b/thread/framework/java/android/net/thread/ThreadNetworkController.java
@@ -754,7 +754,6 @@
 
         for (int i = 0; i < channelMaxPowers.size(); i++) {
             int channel = channelMaxPowers.keyAt(i);
-            int maxPower = channelMaxPowers.get(channel);
 
             if ((channel < ActiveOperationalDataset.CHANNEL_MIN_24_GHZ)
                     || (channel > ActiveOperationalDataset.CHANNEL_MAX_24_GHZ)) {