docs: make kernel-doc handle varargs properly

As far as I can tell, the handling of "..." arguments has never worked
right, so any documentation provided was ignored in favor of "variable
arguments."  This makes kernel-doc handle "@...:" as documented.  It does
*not* fix spots in kerneldoc comments that don't follow that convention,
but they are no more broken than before.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc

@@ -412,7 +412,7 @@ my $doc_com_body = '\s*\* ?';
 my $doc_decl = $doc_com . '(\w+)';
 # @params and a strictly limited set of supported section names
 my $doc_sect = $doc_com . 
-    '\s*(\@\w+|description|context|returns?|notes?|examples?)\s*:(.*)';
+    '\s*(\@[.\w]+|\@\.\.\.|description|context|returns?|notes?|examples?)\s*:(.*)';
 my $doc_content = $doc_com_body . '(.*)';
 my $doc_block = $doc_com . 'DOC:\s*(.*)?';
 my $doc_inline_start = '^\s*/\*\*\s*$';
@@ -2351,6 +2351,7 @@ sub push_parameter($$$) {
 
 	if ($type eq "" && $param =~ /\.\.\.$/)
 	{
+	    $param = "...";
 	    if (!defined $parameterdescs{$param} || $parameterdescs{$param} eq "") {
 		$parameterdescs{$param} = "variable arguments";
 	    }