pm-utils: Fix handling of HVM domains

`xl list` reports the PCI devies for the stub domain. But we want to
call qubes.SuspendPre inside the domain itself.

pm-utils/51qubes-suspend-netvm

@@ -6,7 +6,7 @@ get_running_netvms() {
     RUNNING_NETVMS=""
     for VM in $RUNNING_VMS; do
         if [ -n "`xl pci-list $VM|tail -n +2`" ]; then
-            echo "$VM"
+            echo "${VM%-dm}"
         fi
     done
 }