fix lsun docstring example (#1935)

torchvision/datasets/lsun.py

@@ -67,7 +67,7 @@ class LSUN(VisionDataset):
     Args:
         root (string): Root directory for the database files.
         classes (string or list): One of {'train', 'val', 'test'} or a list of
-            categories to load. e,g. ['bedroom_train', 'church_train'].
+            categories to load. e,g. ['bedroom_train', 'church_outdoor_train'].
         transform (callable, optional): A function/transform that  takes in an PIL image
             and returns a transformed version. E.g, ``transforms.RandomCrop``
         target_transform (callable, optional): A function/transform that takes in the