s390/qeth: silence qeth_fix_features()

Noting the lack of TSO support on every feature change is just silly,
in particular since the requested features might not even affect
NETIF_F_TSO.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>