asyncio: Test fix.

Lib/test/test_asyncio/test_tasks.py

@@ -860,7 +860,7 @@ class TaskTests(unittest.TestCase):
         def runner():
             result = []
             c = coro('ham')
-            for f in asyncio.as_completed({c, c, coro('spam')}, loop=self.loop):
+            for f in asyncio.as_completed([c, c, coro('spam')], loop=self.loop):
                 result.append((yield from f))
             return result