Add missing transaction rollbacks for SQL store (#9964)

* Add missing transaction rollbacks for SQL store

* Add `defer transaction.Rollback()` in SQL stores.

* abstract finalizeTransaction

store/sqlstore/upgrade.go

@@ -173,15 +173,18 @@ func UpgradeDatabaseToVersion33(sqlStore SqlStore) {
 			if err != nil {
 				themeMigrationFailed(err)
 			}
+			defer finalizeTransaction(transaction)
 
 			// increase size of Value column of Preferences table to match the size of the ThemeProps column
 			if sqlStore.DriverName() == model.DATABASE_DRIVER_POSTGRES {
 				if _, err := transaction.Exec("ALTER TABLE Preferences ALTER COLUMN Value TYPE varchar(2000)"); err != nil {
 					themeMigrationFailed(err)
+					return
 				}
 			} else if sqlStore.DriverName() == model.DATABASE_DRIVER_MYSQL {
 				if _, err := transaction.Exec("ALTER TABLE Preferences MODIFY Value text"); err != nil {
 					themeMigrationFailed(err)
+					return
 				}
 			}
 
@@ -196,15 +199,18 @@ func UpgradeDatabaseToVersion33(sqlStore SqlStore) {
 				WHERE
 					Users.ThemeProps != 'null'`, params); err != nil {
 				themeMigrationFailed(err)
+				return
 			}
 
 			// delete old data
 			if _, err := transaction.Exec("ALTER TABLE Users DROP COLUMN ThemeProps"); err != nil {
 				themeMigrationFailed(err)
+				return
 			}
 
 			if err := transaction.Commit(); err != nil {
 				themeMigrationFailed(err)
+				return
 			}
 
 			// rename solarized_* code themes to solarized-* to match client changes in 3.0