[t:2254], put back DB_INHERIT_ISOLATION

git-svn-id: file:///svn/mysql/tokudb-engine/src@16939 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.cc

@@ -3213,7 +3213,7 @@ int ha_tokudb::write_row(uchar * record) {
     }
 
     if (using_ignore) {
-        error = db_env->txn_begin(db_env, transaction, &sub_trans, 0);
+        error = db_env->txn_begin(db_env, transaction, &sub_trans, DB_INHERIT_ISOLATION);
         if (error) {
             goto cleanup;
         }
@@ -3398,7 +3398,7 @@ int ha_tokudb::update_row(const uchar * old_row, uchar * new_row) {
     }
 
     if (using_ignore) {
-        error = db_env->txn_begin(db_env, transaction, &sub_trans, 0 );
+        error = db_env->txn_begin(db_env, transaction, &sub_trans, DB_INHERIT_ISOLATION);
         if (error) {
             goto cleanup;
         }