fix test

Author: Charulata Lodha

test-data/unit/check-async-await.test

@@ -705,7 +705,7 @@ async def f() -> AsyncGenerator[Any, Any]:
 async def h() -> Any:
     yield 0
 
-async def g():  # E: Function is missing a type annotation
+async def g():  # E: Function is missing a return type annotation
     yield 0
 [builtins fixtures/async_await.pyi]
 [typing fixtures/typing-async.pyi]