Replace usage of undocumented logging.WARN

For some reason these are not caught by flake8-logging checks by ruff,
though.

Change-Id: If2c3febf73b49590e3a75f7eac3ffae5fe509d66
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

oslo_privsep/daemon.py

@@ -292,7 +292,7 @@ def fdopen(fd: int, *args: Any, **kwargs: Any) -> Any:
         return open(fd, *args, **kwargs)
 
 
-def _fd_logger(level: int = logging.WARN) -> Any:
+def _fd_logger(level: int = logging.WARNING) -> Any:
     """Helper that returns a file object that is asynchronously logged"""
     read_fd, write_fd = os.pipe()
     read_end = fdopen(read_fd, 'r', 1)

oslo_privsep/tests/unit/test_daemon.py

@@ -99,7 +99,7 @@ class LogTest(testctx.TestContextTestCase):
 
         # These write to the log on the priv side
         logme(logging.DEBUG, 'test@DEBUG')
-        logme(logging.WARN, 'test@WARN')
+        logme(logging.WARNING, 'test@WARN')
 
         time.sleep(0.1)  # Hack to give logging thread a chance to run
 
@@ -123,7 +123,7 @@ class LogTest(testctx.TestContextTestCase):
         )
 
         try:
-            logme(logging.WARN, 'test with exc', exc_info=True)
+            logme(logging.WARNING, 'test with exc', exc_info=True)
         except Exception:  # noqa: S110
             pass
 
@@ -139,7 +139,7 @@ class LogTest(testctx.TestContextTestCase):
             'PrivContext(cfg_section=privsep)', record.processName
         )
         self.assertIn('test_daemon.py', record.exc_text)
-        self.assertEqual(logging.WARN, record.levelno)
+        self.assertEqual(logging.WARNING, record.levelno)
         self.assertEqual('logme', record.funcName)
 
     def test_format_record(self):
@@ -156,7 +156,7 @@ class LogTest(testctx.TestContextTestCase):
             )
         )
 
-        logme(logging.WARN, 'test with exc', exc_info=True)
+        logme(logging.WARNING, 'test with exc', exc_info=True)
 
         time.sleep(0.1)  # Hack to give logging thread a chance to run
 
@@ -204,7 +204,7 @@ class LogTestDaemonTraceback(testctx.TestContextTestCase):
         self.assertIn('Privsep daemon traceback: ', record.getMessage())
         self.assertIsNone(record.exc_info)
         self.assertEqual('MainProcess', record.processName)
-        self.assertEqual(logging.WARN, record.levelno)
+        self.assertEqual(logging.WARNING, record.levelno)
 
 
 @testtools.skipIf(