Fix fine-grained call to write_cache()

Author: Guido van Rossum

mypy/server/update.py

@@ -207,7 +207,7 @@ def update_single(self, module: str, path: str) -> Tuple[List[str],
         # If deleted, module won't be in the graph.
         if module in graph:
             # Generate metadata so that we can reuse the AST in the next run.
-            graph[module].write_cache()
+            graph[module].write_cache(graph)
         for id, state in graph.items():
             # Look up missing ASTs from saved cache.
             if state.tree is None and id in manager.saved_cache:
@@ -352,7 +352,7 @@ def update_single_isolated(module: str,
     state.type_check_first_pass()
     state.type_check_second_pass()
     state.finish_passes()
-    # TODO: state.write_cache()?
+    # TODO: state.write_cache(graph)?
     # TODO: state.mark_as_rechecked()?
 
     graph[module] = state