docs: kdoc: ensure that comments are dropped before calling split_struct_proto()

Changeset 2b957decdb6c ("docs: kdoc: don't add broken comments inside prototypes")
revealed a hidden bug at split_struct_proto(): some comments there may break
its capability of properly identifying a struct.

Fixing it is as simple as stripping comments before calling it.

Fixes: 2b957decdb6c ("docs: kdoc: don't add broken comments inside prototypes")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <dcff37b6da5329aea415de31f543b6a1c2cbbbce.1773770483.git.mchehab+huawei@kernel.org>

tools/lib/python/kdoc/kdoc_parser.py

@@ -723,6 +723,7 @@ class KernelDoc:
         #
         # Do the basic parse to get the pieces of the declaration.
         #
+        proto = trim_private_members(proto)
         struct_parts = self.split_struct_proto(proto)
         if not struct_parts:
             self.emit_msg(ln, f"{proto} error: Cannot parse struct or union!")
@@ -763,6 +764,7 @@ class KernelDoc:
         # Strip preprocessor directives.  Note that this depends on the
         # trailing semicolon we added in process_proto_type().
         #
+        proto = trim_private_members(proto)
         proto = KernRe(r'#\s*((define|ifdef|if)\s+|endif)[^;]*;', flags=re.S).sub('', proto)
         #
         # Parse out the name and members of the enum.  Typedef form first.
@@ -770,7 +772,7 @@ class KernelDoc:
         r = KernRe(r'typedef\s+enum\s*\{(.*)\}\s*(\w*)\s*;')
         if r.search(proto):
             declaration_name = r.group(2)
-            members = trim_private_members(r.group(1))
+            members = r.group(1)
         #
         # Failing that, look for a straight enum
         #
@@ -778,7 +780,7 @@ class KernelDoc:
             r = KernRe(r'enum\s+(\w*)\s*\{(.*)\}')
             if r.match(proto):
                 declaration_name = r.group(1)
-                members = trim_private_members(r.group(2))
+                members = r.group(2)
         #
         # OK, this isn't going to work.
         #