Fix walk processing of %ktcn.
$dtts (lead -.gen %.(+.gen dubs))
$dtwt (lead -.gen %.(+.gen expr))
$ktbr (lead -.gen %.(+.gen expr))
+ $ktcn (lead -.gen %.(+.gen expr))
$ktdt (lead -.gen %.(+.gen dubs))
$ktls (lead -.gen %.(+.gen dubs))
$kthp (lead -.gen %.(+.gen dubs))
