[t:2027], set error=0 on success

git-svn-id: file:///svn/mysql/tokudb-engine/src@14831 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.cc

@@ -993,6 +993,7 @@ int create_tokudb_trx_data_instance(tokudb_trx_data** out_trx) {
     trx->iso_level = hatoku_iso_not_set;
 
     *out_trx = trx;
+    error = 0;
 cleanup:
     return error;
 }