port -r21376 from trunk : unregister pointer when reusing memory chunk

src/datawizard/memalloc.c

@@ -443,6 +443,7 @@ static void reuse_mem_chunk(unsigned node, struct _starpu_data_replicate *new_re
 	struct _starpu_data_replicate *old_replicate = mc->replicate;
 	if (old_replicate)
 	{
+		_starpu_data_unregister_ram_pointer(old_replicate->handle, node);
 		old_replicate->allocated = 0;
 		old_replicate->automatically_allocated = 0;
 		old_replicate->initialized = 0;