Merge pull request #6172 from taosdata/cq

fix memory leak when calloc sqlstr error.

src/client/src/tscStream.c

@@ -623,6 +623,7 @@ TAOS_STREAM *taos_open_stream(TAOS *taos, const char *sqlstr, void (*fp)(void *p
   if (pSql->sqlstr == NULL) {
     tscError("0x%"PRIx64" failed to malloc sql string buffer", pSql->self);
     tscFreeSqlObj(pSql);
+    free(pStream);
     return NULL;
   }