staging: vt6656: struct vnt_usb_send_context remove sEthHeader.

In nsDMA_tx_packet and bRelayPacketSend s_vSaveTxPktInfo points
to sEthHeader.h_dest which is the wrong viable.

Correct and point to pDevice->sTxEthHeader.

This is only relevant in the non fuctioning hostapd access point
mode, shortly to be removed from driver.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>