docs: kdoc_parser: don't mangle with function defines

docs: kdoc_parser: don't mangle with function defines

Mangling with #defines is not nice, as we may end removing
the macro names, preventing several macros from being properly
documented.

Also, on defines, we have something like:

	#define foo(a1, a2, a3, ...)			 \
		/* some real implementation */

The prototype part (first line on this example) won't contain
any macros, so no need to apply any regexes on it.

With that, move the apply_transforms() logic to ensure that
it will be called only on functions.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <8f9854c8ca1c794b6a3fe418f7adbc32aa68b432.1772469446.git.mchehab+huawei@kernel.org>