Fix a misnamed test for lists. (GH-11933)

diff --git a/Lib/test/list_tests.py b/Lib/test/list_tests.py
index ed63fda..40316de 100644
--- a/Lib/test/list_tests.py
+++ b/Lib/test/list_tests.py
@@ -31,9 +31,15 @@
         self.assertEqual(a, b)
 
     def test_getitem_error(self):
+        a = []
         msg = "list indices must be integers or slices"
         with self.assertRaisesRegex(TypeError, msg):
-            a = []
+            a['a']
+
+    def test_setitem_error(self):
+        a = []
+        msg = "list indices must be integers or slices"
+        with self.assertRaisesRegex(TypeError, msg):
             a['a'] = "python"
 
     def test_repr(self):