[MM-31398] upgrade error level to critical in case of panic or os.Exit (#16584)

* upgrade error level to critical in case of panic or os.Exit

* reflect revivew comments

* fix error capitalization

store/sqlstore/upgrade.go

@@ -847,7 +847,7 @@ func upgradeDatabaseToVersion527(sqlStore *SqlStore) {
 func upgradeDatabaseToVersion528(sqlStore *SqlStore) {
 	if shouldPerformUpgrade(sqlStore, VERSION_5_27_0, VERSION_5_28_0) {
 		if err := precheckMigrationToVersion528(sqlStore); err != nil {
-			mlog.Error("Error upgrading DB schema to 5.28.0", mlog.Err(err))
+			mlog.Critical("Error upgrading DB schema to 5.28.0", mlog.Err(err))
 			os.Exit(EXIT_GENERIC_FAILURE)
 		}