ramips: Fix bridging in ramips ethernet driver

ramips: Fix bridging in ramips ethernet driver

Bridging between the ramips ethernet driver and rt2800pci was somewhat
broken. Frames received by the ethernet driver which were passed to the
wifi driver for transmission were sometimes corrupted or sent out with
huge delays.

The reason for this is the missing assignment of skb->tail in the ramips
ethernet driver's rx path resulting in skb->tail pointing to skb->data.
Since skb->tail is used by mac80211 it writes into skb->data which messes
up the frames content.

Fix this by using skb_put to correctly set skb->len and skb->tail.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@22172 3c298f89-4303-0410-b956-a3cf2f4a3e73