Minor fix in DummyStorageReader test mock (#1034)

Summary:
Pull Request resolved: #1034

Minor fix in DummyStorageReader test mock. Incorrect method was mocked.

Reviewed By: Saiteja64

Differential Revision: D73602438

fbshipit-source-id: 5c258f3ec8f5a482118a5b721cdd1ec1508489b1

Author: saumishr

tests/framework/callbacks/test_dcp_saver.py

@@ -1022,7 +1022,7 @@ class DummyStorageReader(FileSystemReader):
     def __init__(self, path: str) -> None:
         super().__init__(path)
 
-    def set_up_storage_writer(
+    def set_up_storage_reader(
         self, is_coordinator: bool, *args: Any, **kwargs: Any
     ) -> None:
         pass