net/mlx5e: Count LRO packets correctly

RX packets statistics ('rx_packets' counter) used to count LRO packets
as one, even though it contains multiple segments.
This patch will increment the counter by the number of segments, and
align the driver with the behavior of other drivers in the stack.

Note that no information is lost in this patch due to 'rx_lro_packets'
counter existence.

Before, ethtool showed:
$ ethtool -S ens6 | egrep "rx_packets|rx_lro_packets"
     rx_packets: 435277
     rx_lro_packets: 35847
     rx_packets_phy: 1935066

Now, we will see the more logical statistics:
$ ethtool -S ens6 | egrep "rx_packets|rx_lro_packets"
     rx_packets: 1935066
     rx_lro_packets: 35847
     rx_packets_phy: 1935066

Fixes: e586b3b0 ("net/mlx5: Ethernet Datapath files")
Signed-off-by: Gal Pressman <galp@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>