fix(stream): fix memory leak.

source/dnode/mnode/impl/src/mndScheduler.c

@@ -546,14 +546,16 @@ static int32_t addSourceTasksForMultiLevelStream(SMnode* pMnode, SQueryPlan* pPl
     if (pStream->conf.fillHistory) {
       code = doAddSourceTask(pHSourceTaskList, pStream->conf.fillHistory, pStream->hTaskUid, pHDownstreamTask, pMnode,
                              plan, pVgroup);
-      sdbRelease(pSdb, pVgroup);
 
       if (code != TSDB_CODE_SUCCESS) {
+        sdbRelease(pSdb, pVgroup);
         return code;
       }
 
       setHTasksId(pSourceTaskList, pHSourceTaskList);
     }
+
+    sdbRelease(pSdb, pVgroup);
   }
 
   return TSDB_CODE_SUCCESS;

source/dnode/mnode/impl/src/mndStream.c

@@ -1001,8 +1001,6 @@ static int32_t mndProcessStreamDoCheckpoint(SRpcMsg *pReq) {
 static int32_t mndProcessDropStreamReq(SRpcMsg *pReq) {
   SMnode     *pMnode = pReq->info.node;
   SStreamObj *pStream = NULL;
-  /*SDbObj     *pDb = NULL;*/
-  /*SUserObj   *pUser = NULL;*/
 
   SMDropStreamReq dropReq = {0};
   if (tDeserializeSMDropStreamReq(pReq->pCont, pReq->contLen, &dropReq) < 0) {