tests: aux fallback to sleep

When dbus-send tool is not present on system, fallback to sleep.

test/lib/aux.sh

@@ -323,11 +323,15 @@ prepare_lvmdbusd() {
 	local pid=$!
 
 	echo -n "## checking lvmdbusd IS running..."
+	if which dbus-send &>/dev/null ; then
 	for i in {50..0}; do
 		dbus-send --system --dest=org.freedesktop.DBus --type=method_call --print-reply /org/freedesktop/DBus org.freedesktop.DBus.ListNames > dbus_services
 		grep -q com.redhat.lvmdbus1 dbus_services && break
 		sleep .1
 	done
+	else
+		sleep 2
+	fi
 
 	if [ "$i" -eq 0 ] ; then
 		printf "\nFailed to serve lvm dBus service in 5 seconds.\n"