add updating random machine

clientside/tmcc/common/nodetest/usr/local/etc/emulab/update

@@ -21,6 +21,12 @@ utils="diskcheck diskspeedcheck memcheck cpucheck checkutils.sh getfromtb.sh hbi
 
 arg=${arg=""} # use var if set else use ""
 
+case $arg in
+    drive | disk | mem | cpu | diskspeed | time | nic | Ngetlogs | clearlogs | help | -help | -h | ? ) ;;
+    pc* )
+	list=$arg ;;
+esac
+
 case $arg in
     # don't need OS if not 
     drive | disk | mem | cpu | diskspeed | time | nic | Ngetlogs | clearlogs | help | -help | -h | ? ) machines=$list ;;