bnxt_en: Don't set ETS on unused TCs.

Currently, the code allows ETS bandwidth weight 0 to be set on unused TCs.
We should not set any DCB parameters on unused TCs at all.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c

@@ -471,6 +471,9 @@ static int bnxt_ets_validate(struct bnxt *bp, struct ieee_ets *ets, u8 *tc)
 	if (total_ets_bw > 100)
 		return -EINVAL;
 
+	if (max_tc >= bp->max_tc)
+		*tc = bp->max_tc;
+	else
 		*tc = max_tc + 1;
 	return 0;
 }