Hotfix/sangshuduo/td 3197 taosdemo coverity scan for master (#6725)

* [TD-3197]<fix>: taosdemo and taosdump coverity scan issues.

* exit if read sample file failed.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

src/kit/taosdemo/taosdemo.c

@@ -4702,14 +4702,18 @@ PARSE_OVER:
   return ret;
 }
 
-static void prepareSampleData() {
+static int prepareSampleData() {
   for (int i = 0; i < g_Dbs.dbCount; i++) {
     for (int j = 0; j < g_Dbs.db[i].superTblCount; j++) {
       if (g_Dbs.db[i].superTbls[j].tagsFile[0] != 0) {
-        (void)readTagFromCsvFileToMem(&g_Dbs.db[i].superTbls[j]);
+        if (readTagFromCsvFileToMem(&g_Dbs.db[i].superTbls[j]) != 0) {
+          return -1;
+        }
       }
     }
   }
+
+  return 0;
 }
 
 static void postFreeResource() {
@@ -6771,7 +6775,11 @@ static int insertTestProcess() {
   }
 
   // pretreatement
-  prepareSampleData();
+  if (prepareSampleData() != 0) {
+    if (g_fpOfInsertResult)
+      fclose(g_fpOfInsertResult);
+    return -1;
+  }
 
   double start;
   double end;