Minor performance wins.

common/io/kicad/kicad_io_utils.cpp

@@ -224,7 +224,7 @@ void Prettify( std::string& aSource, char aQuoteChar )
         ++cursor;
     }
 
-    aSource = formatted;
+    aSource = std::move( formatted );
 }
 
 } // namespace KICAD_FORMAT

common/view/view.cpp

@@ -683,7 +683,7 @@ void VIEW::ReorderLayerData( std::unordered_map<int, int> aReorderMap )
         new_map[pair.second].id = pair.second;
     }
 
-    m_layers = new_map;
+    m_layers = std::move( new_map );
 
     for( VIEW_ITEM* item : *m_allItems )
     {