bpo-36373: Fix deprecation warnings (GH-15889)



https://bugs.python.org/issue36373
diff --git a/Lib/asyncio/locks.py b/Lib/asyncio/locks.py
index f63d4ce..d94daeb 100644
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -332,7 +332,7 @@
                           DeprecationWarning, stacklevel=2)
 
         if lock is None:
-            lock = Lock(loop=self._loop)
+            lock = Lock(loop=loop)
         elif lock._loop is not self._loop:
             raise ValueError("loop argument must agree with lock")