s390/qeth: fix off-by-one in RX copybreak check

The RX copybreak is intended as the _max_ value where the frame's data
should be copied. So for frame_len == copybreak, don't build an SG skb.

Fixes: 4a71df5 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core_main.c

@@ -5344,7 +5344,7 @@ static int qeth_extract_skb(struct qeth_card *card,
 	}
 
 	use_rx_sg = (card->options.cq == QETH_CQ_ENABLED) ||
-		    ((skb_len >= card->options.rx_sg_cb) &&
+		    (skb_len > card->options.rx_sg_cb &&
 		     !atomic_read(&card->force_alloc_skb) &&
 		     !IS_OSN(card));