Fix a logic error so mtu works.

bug:17046179
Change-Id: I744a2fd425627da16d9779df3a96541506e0b6b3
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 02695c5..92953cc 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -1534,7 +1534,7 @@
             return;
         }
 
-        if (LinkProperties.isValidMtu(mtu, newLp.hasGlobalIPv6Address())) {
+        if (LinkProperties.isValidMtu(mtu, newLp.hasGlobalIPv6Address()) == false) {
             loge("Unexpected mtu value: " + mtu + ", " + iface);
             return;
         }