fix TSDB memory leak

src/tsdb/src/tsdbMemTable.c

@@ -587,6 +587,7 @@ static int tsdbCommitToFile(STsdbRepo *pRepo, int fid, SCommitIter *iters, SRWHe
     goto _err;
   }
 
+  tfree(dataDir);
   tsdbCloseHelperFile(pHelper, 0);
 
   pthread_rwlock_wrlock(&(pFileH->fhlock));