staging: et131x: Remove some unecessary packet accounting code

The ce_stats ipackets and opackets members are only used to update
the net_device_stats->[r,t]x_packets counters, so get rid of them.

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