debian: place build utilities in a single file

debian/rules

@@ -78,7 +78,7 @@ override_dh_auto_test:
 
 override_dh_strip:
 	dh_strip -a -k
-	./debian/create-dbg-pkgs.sh
+	./debian/util.sh create-dbg-pkgs
 
 override_dh_auto_install:
 	dh_auto_install

debian/create-dbg-pkgs.sh → debian/util.sh

@@ -13,5 +13,9 @@ create_dbg_pkgs () {
   done
 }
 
-create_dbg_pkgs
+cmd="$1"
+shift
+case "$cmd" in
+  create-dbg-pkgs) create_dbg_pkgs ;;
+esac