bug: revert code, mv ret value from try block back to catch block

[hustjieke]

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Please confirm if bug report does NOT exists already ?

• I confirm there is no existing issue for this

Describe the problem

Before, we set ret = 1 if catch a throw, but in pr 0be195a, set ret action has been moved to try block, not efficient, every time we do truncate success, ret will be setted to 1.

1225 int ha_tianmu::truncate() {
1226   DBUG_ENTER(__PRETTY_FUNCTION__);
1227   int ret = 1;
1228   try {
1229     ha_tianmu_engine_->TruncateTable(table_name_, ha_thd());
1230     ret = 0;
1231   } catch (std::exception &e) {
1232     TIANMU_LOG(LogCtl_Level::ERROR, "An exception is caught: %s", e.what());
1233   } catch (...) {
1234     TIANMU_LOG(LogCtl_Level::ERROR, "An unknown system exception error caught.");
1235   }
1236   DBUG_RETURN(ret);
1237 }

Expected behavior

move back to catch block.

1225 int ha_tianmu::truncate() {
1226   DBUG_ENTER(__PRETTY_FUNCTION__);
1227   int ret = 0;
1228   try {
1229     ha_tianmu_engine_->TruncateTable(table_name_, ha_thd());
1230   } catch (std::exception &e) {
1231     TIANMU_LOG(LogCtl_Level::ERROR, "An exception is caught: %s", e.what());
1232     ret = 1;
1233   } catch (...) {
1234     TIANMU_LOG(LogCtl_Level::ERROR, "An unknown system exception error caught.");
1235     ret = 1;
1236   }
1237   DBUG_RETURN(ret);
1238 }

How To Reproduce

No response

Environment

No response

Are you interested in submitting a PR to solve the problem?

• Yes, I will!