etraxfs_eth: Drop eth_can_receive

True is the default.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Message-id: 1435734647-8371-3-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>