Re #6198. Fix last use of mapping method in Framework.

We're relying on the move assignment operator here for efficiency, so
things will be a little slower on the Mac until it gets C++11 libs.
But we're not leaking the thing like we were before.

Code/Mantid/Framework/LiveData/inc/MantidLiveData/SNSLiveEventDataListener.h

@@ -120,7 +120,7 @@ namespace Mantid
 
       bool m_workspaceInitialized;
       std::string m_wsName;
-      detid2index_map * m_indexMap;  // maps pixel id's to workspace indexes
+      detid2index_map m_indexMap;  // maps pixel id's to workspace indexes
 
       // We need these 2 strings to initialize m_buffer
       std::string m_instrumentName;

Code/Mantid/Framework/LiveData/src/SNSLiveEventDataListener.cpp

@@ -1180,8 +1180,8 @@ namespace LiveData
   {
     // It'd be nice to use operator[], but we might end up inserting a value....
     // Have to use find() instead.
-    detid2index_map::iterator it = m_indexMap->find( pixelId);
-    if (it != m_indexMap->end())
+    detid2index_map::iterator it = m_indexMap.find( pixelId);
+    if (it != m_indexMap.end())
     {
       std::size_t workspaceIndex = it->second;
       Mantid::DataObjects::TofEvent event( tof, pulseTime);