Merge pull request #16788 from taosdata/fix/memory_leak

fix: alter table memory leakage

source/dnode/vnode/src/meta/metaTable.c

@@ -244,6 +244,7 @@ int metaDropSTable(SMeta *pMeta, int64_t verison, SVDropStbReq *pReq, SArray *tb
   // check if super table exists
   rc = tdbTbGet(pMeta->pNameIdx, pReq->name, strlen(pReq->name) + 1, &pData, &nData);
   if (rc < 0 || *(tb_uid_t *)pData != pReq->suid) {
+    tdbFree(pData);
     terrno = TSDB_CODE_TDB_STB_NOT_EXIST;
     return -1;
   }