staging: et131x: Remove ununsed statistics

From struct ce_stats; unicast_pkts_rcvd, unicast_pkts_xmtd,
multicast_pkts_xmtd, broadcast_pkts_rcvd and broadcast_pkts_xmtd
are not returned or used for anything meaningful - remove the code
that collects them, and the struct members too.

Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>