dpaa2-eth: Fix possible access beyond end of array

Make sure we don't try to enqueue XDP_REDIRECT frames to an
inexistent FQ.

While it is guaranteed not to have more than one queue per core,
having fewer queues than CPUs on an interface is a valid
configuration.

Fixes: d678be1d ("dpaa2-eth: add XDP_REDIRECT support")
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c

@@ -1817,7 +1817,7 @@ static int dpaa2_eth_xdp_xmit_frame(struct net_device *net_dev,
 	dpaa2_fd_set_format(&fd, dpaa2_fd_single);
 	dpaa2_fd_set_ctrl(&fd, FD_CTRL_PTA);
 
-	fq = &priv->fq[smp_processor_id()];
+	fq = &priv->fq[smp_processor_id() % dpaa2_eth_queue_count(priv)];
 	for (i = 0; i < DPAA2_ETH_ENQUEUE_RETRIES; i++) {
 		err = priv->enqueue(priv, fq, &fd, 0);
 		if (err != -EBUSY)