Workaround invocations from installation of power-management packages.

Index: hurd-debian/sutils/MAKEDEV.sh
===================================================================
--- hurd-debian.orig/sutils/MAKEDEV.sh
+++ hurd-debian/sutils/MAKEDEV.sh
@@ -223,6 +223,9 @@ mkdev() {
         st $I root 640 /hurd/null
 	;;
 
+      apm)
+        ;;
+
       *)
 	lose "$I: Unknown device name"
 	;;