Don't use NPP for connection handover.

Handover will only work with SNEP; if SNEP fails,
don't try with NPP.

Change-Id: Ib92c90cb588b99e177fa1c70b89753ef8d0e16ea
diff --git a/src/com/android/nfc/P2pLinkManager.java b/src/com/android/nfc/P2pLinkManager.java
index ecded75..2f70f39 100755
--- a/src/com/android/nfc/P2pLinkManager.java
+++ b/src/com/android/nfc/P2pLinkManager.java
@@ -405,7 +405,11 @@
                     return null;
                 }
 
-                result = new NdefPushClient().push(m);
+                if (m != null) {
+                    result = new NdefPushClient().push(m);
+                } else {
+                    result = false;
+                }
             }
             time = SystemClock.elapsedRealtime() - time;