dnp3: fix coverity CID 1374300

src/output-json-alert.c

@@ -145,16 +145,13 @@ static void AlertJsonSsh(const Flow *f, json_t *js)
 static void AlertJsonDnp3(const Flow *f, json_t *js)
 {
     DNP3State *dnp3_state = (DNP3State *)FlowGetAppState(f);
-    json_t *dnp3js = NULL;
     if (dnp3_state) {
         uint64_t tx_id = AppLayerParserGetTransactionLogId(f->alparser);
         DNP3Transaction *tx = AppLayerParserGetTx(IPPROTO_TCP, ALPROTO_DNP3,
             dnp3_state, tx_id);
         if (tx) {
             json_t *dnp3js = json_object();
-            if (unlikely(dnp3js == NULL)) {
+            if (likely(dnp3js != NULL)) {
-                goto error;
-            }
                 if (tx->has_request && tx->request_done) {
                     json_t *request = JsonDNP3LogRequest(tx);
                     if (request != NULL) {
@@ -170,12 +167,9 @@ static void AlertJsonDnp3(const Flow *f, json_t *js)
                 json_object_set_new(js, "dnp3", dnp3js);
             }
         }
+    }
 
     return;
-error:
-    if (dnp3js != NULL) {
-        json_decref(dnp3js);
-    }
 }
 
 void AlertJsonHeader(const Packet *p, const PacketAlert *pa, json_t *js)