dpdk: reset stats just before the start of packet receive loop

While Suricata initializes, the device must be started to e.g.
apply rte_flow rules on some devices. But in the meantime, the
NIC started receiving packets but accounted those as missed.
Stats reset was added to better represent true packet drop.

src/source-dpdk.c

@@ -373,8 +373,10 @@ static TmEcode ReceiveDPDKLoop(ThreadVars *tv, void *data, void *slot)
     // Indicate that the thread is actually running its application level code (i.e., it can poll
     // packets)
     TmThreadsSetFlag(tv, THV_RUNNING);
-
     PacketPoolWait();
+
+    rte_eth_stats_reset(ptv->port_id);
+    rte_eth_xstats_reset(ptv->port_id);
     while (1) {
         if (unlikely(suricata_ctl_flags != 0)) {
             SCLogDebug("Stopping Suricata!");