fix: coverity issues

CID: 400220

docs/examples/c/tmq_example.c

@@ -184,22 +184,54 @@ void tmq_commit_cb_print(tmq_t* tmq, int32_t code, void* param) {
 tmq_t* build_consumer() {
   tmq_conf_res_t code;
   tmq_conf_t*    conf = tmq_conf_new();
+
   code = tmq_conf_set(conf, "enable.auto.commit", "true");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "auto.commit.interval.ms", "1000");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "group.id", "cgrpName");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "client.id", "user defined name");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "td.connect.user", "root");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "td.connect.pass", "taosdata");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "auto.offset.reset", "earliest");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
+
   code = tmq_conf_set(conf, "experimental.snapshot.enable", "false");
-  if (TMQ_CONF_OK != code) return NULL;
+  if (TMQ_CONF_OK != code) {
+    tmq_conf_destroy(conf);
+    return NULL;
+  }
 
   tmq_conf_set_auto_commit_cb(conf, tmq_commit_cb_print, NULL);