docs: kdoc: fix logic to handle unissued warnings

docs: kdoc: fix logic to handle unissued warnings

Changeset 469c1c9eb6c9 ("kernel-doc: Issue warnings that were silently discarded")
didn't properly addressed the missing messages behavior, as
it was calling directly python logger low-level function,
instead of using the expected method to emit warnings.

Basically, there are two methods to log messages:

- self.config.log.warning() - This is the raw level to emit a
  warning. It just writes the a message at stderr, via python
  logging, as it is initialized as:

    self.config.log = logging.getLogger("kernel-doc")

- self.config.warning() - This is where we actually consider a
  message as a warning, properly incrementing error count.

Due to that, several parsing error messages are internally considered
as success, causing -Werror to not work on such messages.

While here, ensure that the last ignored entry will also be handled
by adding an extra check at the end of the parse handler.

Fixes: 469c1c9eb6c9 ("kernel-doc: Issue warnings that were silently discarded")
Closes: https://lore.kernel.org/linux-doc/20260112091053.00cee29a@foz.lan/
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <95109a6585171da4d6900049deaa2634b41ee743.1768823489.git.mchehab+huawei@kernel.org>