netdev: bfin_mac: handler RX status errors

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>