ethernet: delete superfluous helper function

isCurrentCallback() is a trivial one liner that is more readable
inlined.
This change also renames handleIpEvent() to safelyPostOnHandler() to be
more descriptive.

Test: TH
Change-Id: I9224c9555f0b2ed22ff1cec5ae1c6e870c16820b
diff --git a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
index 6776920..ece10f3 100644
--- a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
+++ b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
@@ -313,17 +313,12 @@
                 mIpClientShutdownCv.block();
             }
 
-            // At the time IpClient is stopped, an IpClient event may have already been posted on
-            // the back of the handler and is awaiting execution. Once that event is executed, the
-            // associated callback object may not be valid anymore
-            // (NetworkInterfaceState#mIpClientCallback points to a different object / null).
-            private boolean isCurrentCallback() {
-                return this == mIpClientCallback;
-            }
-
-            private void handleIpEvent(final @NonNull Runnable r) {
+            private void safelyPostOnHandler(Runnable r) {
                 mHandler.post(() -> {
-                    if (!isCurrentCallback()) {
+                    if (this != mIpClientCallback) {
+                        // At the time IpClient is stopped, an IpClient event may have already been
+                        // posted on the handler and is awaiting execution. Once that event is
+                        // executed, the associated callback object may not be valid anymore.
                         Log.i(TAG, "Ignoring stale IpClientCallbacks " + this);
                         return;
                     }
@@ -333,24 +328,24 @@
 
             @Override
             public void onProvisioningSuccess(LinkProperties newLp) {
-                handleIpEvent(() -> onIpLayerStarted(newLp));
+                safelyPostOnHandler(() -> onIpLayerStarted(newLp));
             }
 
             @Override
             public void onProvisioningFailure(LinkProperties newLp) {
                 // This cannot happen due to provisioning timeout, because our timeout is 0. It can
                 // happen due to errors while provisioning or on provisioning loss.
-                handleIpEvent(() -> onIpLayerStopped());
+                safelyPostOnHandler(() -> onIpLayerStopped());
             }
 
             @Override
             public void onLinkPropertiesChange(LinkProperties newLp) {
-                handleIpEvent(() -> updateLinkProperties(newLp));
+                safelyPostOnHandler(() -> updateLinkProperties(newLp));
             }
 
             @Override
             public void onReachabilityLost(String logMsg) {
-                handleIpEvent(() -> updateNeighborLostEvent(logMsg));
+                safelyPostOnHandler(() -> updateNeighborLostEvent(logMsg));
             }
 
             @Override