This fixes two errors when building iso filesystem:
a) dir root.grub/boot doesn't get created.
b) the creation of .image file by gen_image.sh which apparently is not needed
when building an iso.
Signed-off-by: Vasilis Tsiligiannis <b_tsiligiannis@silverton.gr>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15682 3c298f89-4303-0410-b956-a3cf2f4a3e73