Android: Fix return value in createSurface()

When the function fails it should return -1

Change-Id: I132a1521897295e6e232126ca51e30d2e32656c8
Reviewed-by: BogDan Vatra <bogdan@kde.org>

src/plugins/platforms/android/androidjnimain.cpp

@@ -337,7 +337,7 @@ namespace QtAndroid
     {
         QJNIEnvironmentPrivate env;
         if (!env)
-            return 0;
+            return -1;
 
         m_surfacesMutex.lock();
         int surfaceId = m_surfaceId++;