Always reset alert cnt and always increment det_ctx->pkts.

src/detect.c

@@ -1278,15 +1278,14 @@ int SigMatchSignatures(ThreadVars *th_v, DetectEngineCtx *de_ctx, DetectEngineTh
 
     SCLogDebug("pcap_cnt %"PRIu64, p->pcap_cnt);
 
+    p->alerts.cnt = 0;
+    det_ctx->pkts++;
+
     /* No need to perform any detection on this packet, if the the given flag is set.*/
     if (p->flags & PKT_NOPACKET_INSPECTION) {
         SCReturnInt(0);
     }
 
-    p->alerts.cnt = 0;
-
-    det_ctx->pkts++;
-
     /* grab the protocol state we will detect on */
     if (p->flags & PKT_HAS_FLOW) {
         if (p->flags & PKT_STREAM_EOF) {