MDLLoader: Replace raw pointer with vector to fix a memory leak

code/MDLFileData.h

@@ -844,11 +844,11 @@ struct IntGroupInfo_MDL7
 struct IntGroupData_MDL7
 {
     IntGroupData_MDL7()
-        : pcFaces(NULL), bNeed2UV(false)
+        : bNeed2UV(false)
     {}
 
     //! Array of faces that belong to the group
-    MDL::IntFace_MDL7* pcFaces;
+    std::vector<MDL::IntFace_MDL7> pcFaces;
 
     //! Array of vertex positions
     std::vector<aiVector3D>     vPositions;