Update test_errno from v3.14.3

Lib/test/test_errno.py

@@ -12,14 +12,12 @@ class ErrnoAttributeTests(unittest.TestCase):
     def test_for_improper_attributes(self):
         # No unexpected attributes should be on the module.
         for error_code in std_c_errors:
-            self.assertTrue(hasattr(errno, error_code),
-                            "errno is missing %s" % error_code)
+            self.assertHasAttr(errno, error_code)
 
     def test_using_errorcode(self):
         # Every key value in errno.errorcode should be on the module.
         for value in errno.errorcode.values():
-            self.assertTrue(hasattr(errno, value),
-                            'no %s attr in errno' % value)
+            self.assertHasAttr(errno, value)
 
 
 class ErrorcodeTests(unittest.TestCase):