adhoc-osx: fixing recently introduced bug in debug mode (with logging)

Change-Id: Iebd6c107fb115a178549ac9669ae33bfd27448f5
diff --git a/adhoc/adhoc-osx.mm b/adhoc/adhoc-osx.mm
index b58bdd4..a5f1c70 100644
--- a/adhoc/adhoc-osx.mm
+++ b/adhoc/adhoc-osx.mm
@@ -54,7 +54,7 @@
   CWInterface *airport = [CWInterface interfaceWithName:interfaceName];
 
   g_priorNetwork = airport.ssid;
-  _LOG_DEBUG ("Prior network: " << [_priorNetwork cStringUsingEncoding:NSASCIIStringEncoding]);
+  _LOG_DEBUG ("Prior network: " << [g_priorNetwork cStringUsingEncoding:NSASCIIStringEncoding]);
 
   _LOG_DEBUG ("Starting adhoc connection");