[package] fstools: update to the latest version

Fixes RO mounts on imx6 target.

Signed-off-by: Luka Perkov <luka@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40818 3c298f89-4303-0410-b956-a3cf2f4a3e73