[PATCH] [qos-scripts] Fix packet/connection marking when using halfduplex option

This fixes an bug where QoS is not applied to packets passing through
POSTROUTING chain when using halfduplex option. Since QoS is done on IMQ
device, packets should be marked before sending to the IMQ.
Signed-off-by: Vasilis Tsiligiannis <b_tsiligiannis@silverton.gr>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15947 3c298f89-4303-0410-b956-a3cf2f4a3e73