scripts: kernel-doc: prevent a KeyError when checking output

If a file sent to KernelFiles.msg() method doesn't exist, instead
of producing a KeyError, output an error message.

Reported-by: Randy Dunlap <[email protected]>
Closes: https://lore.kernel.org/linux-doc/[email protected]/T/#ma43ae9d8d0995b535cf5099e5381dace0410de04
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: Akira Yokosawa <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>
Message-ID: <4efa177f2157a7ec009cc197dfc2d87e6f32b165.1747817887.git.mchehab+huawei@kernel.org>

Author: mchehab

scripts/lib/kdoc/kdoc_files.py

@@ -271,6 +271,10 @@ def msg(self, enable_lineno=False, export=False, internal=False,
                                       no_doc_sections)
 
             msg = ""
+            if fname not in self.results:
+                self.config.log.warning("No kernel-doc for file %s", fname)
+                continue
+
             for name, arg in self.results[fname]:
                 m = self.out_msg(fname, name, arg)