Fix a bug where an attribute was lacking an object to work off of.

Related to the fix for issue #9572. Thanks to Ɓukasz Czuja for catching the
bug.
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 35b42ca..5566b78 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -499,7 +499,7 @@
                     continue
                 # If can't get proper access, then just forget about writing
                 # the data.
-                elif errno == errno.EACCES:
+                elif exc.errno == errno.EACCES:
                     return
                 else:
                     raise