fixes 2 bugs
* typo
* use %04d rather than %d when printing the position
Signed-off-by: John Crispin <blogic@openwrt.org>

Backport of r46666

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@46675 3c298f89-4303-0410-b956-a3cf2f4a3e73