app/testpmd: revert MAC update in checksum forwarding

[ upstream commit 9b4ea7ae77faa8f8aba8c7510c821f75d7863b16 ]

This patch reverts
commit 10f4620 ("app/testpmd: modify mac in csum forwarding"),
as the checksum forwarding is expected to only perform
checksum and not also overwrites the source and destination MAC addresses.

Doing so, we can test checksum offloading with real traffic
without breaking broadcast packets.

Fixes: 10f4620 ("app/testpmd: modify mac in csum forwarding")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Chenbo Xia <chenbo.xia@intel.com>
Acked-by: Aman Singh <aman.deep.singh@intel.com>

app/test-pmd/csumonly.c

@@ -846,10 +846,6 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 		 * and inner headers */
 
 		eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
-		rte_ether_addr_copy(&peer_eth_addrs[fs->peer_addr],
-				&eth_hdr->d_addr);
-		rte_ether_addr_copy(&ports[fs->tx_port].eth_addr,
-				&eth_hdr->s_addr);
 		parse_ethernet(eth_hdr, &info);
 		l3_hdr = (char *)eth_hdr + info.l2_len;