bpo-18374: fix tests to check the correct thing about line numbers (GH-14659)

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 1e07c57..6bd27ce 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -598,14 +598,14 @@
         self.assertEqual(parent_binop.end_lineno, 2)
 
         self.assertEqual(child_binop.col_offset, 0)
-        self.assertEqual(parent_binop.lineno, 1)
+        self.assertEqual(child_binop.lineno, 1)
         self.assertEqual(child_binop.end_col_offset, 2)
-        self.assertEqual(parent_binop.end_lineno, 2)
+        self.assertEqual(child_binop.end_lineno, 2)
 
         self.assertEqual(grandchild_binop.col_offset, 0)
-        self.assertEqual(parent_binop.lineno, 1)
+        self.assertEqual(grandchild_binop.lineno, 1)
         self.assertEqual(grandchild_binop.end_col_offset, 3)
-        self.assertEqual(parent_binop.end_lineno, 2)
+        self.assertEqual(grandchild_binop.end_lineno, 1)
 
 class ASTHelpers_Test(unittest.TestCase):
     maxDiff = None