Some packets are discarded by the NIC because they are larger than
the MTU, these packets should be counted as "RX error" instead of
"RX packet", for example:
---------------- Forward statistics for port 0 -----------------
RX-packets: 2 RX-dropped: 0 RX-total: 2
TX-packets: 1 TX-dropped: 0 TX-total: 1
----------------------------------------------------------------
Here the packet pkt2 has been discarded, but still was counted
by "RX-packets"
The register 'GL_RXERR1' can count above discarded packets.
This patch adds reading and calculation of the 'GL_RXERR1' counter
when reporting DPDK statistics.