Added missing finalizer

#996

Author: aienabled

Source/SharpDX/DataStream.cs

@@ -203,6 +203,11 @@ internal unsafe DataStream(void* buffer, int sizeInBytes, bool canRead, bool can
             _canWrite = canWrite;
             _ownsBuffer = makeCopy;
         }
+        
+        ~DataStream()
+        {
+            Dispose(false);
+        }
 
         /// <summary>
         /// Releases unmanaged and - optionally - managed resources