fix comment about what pnpinfo is set

etc/devd.conf

@@ -155,7 +155,8 @@ attach 0 {
 
 # Don't even try to second guess what to do about drivers that don't
 # match here.  Instead, pass it off to syslog.  Commented out for the
-# moment, as pnpinfo isn't set in devd yet.
+# moment, as the pnpinfo variable isn't set in devd yet.  Individual
+# variables within the bus supplied pnpinfo are set.
 nomatch 0 {
 #	action "logger Unknown device: $pnpinfo $location $bus";
 };