Refactor: DRY VoltZK.restore_barrier symbol.
Refactor: DRY VoltZK.restore_barrier symbol.

VoltDB/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,paulmartel/voltdb,ingted/voltdb,VoltDB/voltdb,migue/voltdb,creative-quant/voltdb,kobronson/cs-voltdb,deerwalk/voltdb,flybird119/voltdb,zuowang/voltdb,paulmartel/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,deerwalk/voltdb,flybird119/voltdb,VoltDB/voltdb,ingted/voltdb,kumarrus/voltdb,VoltDB/voltdb,zuowang/voltdb,kobronson/cs-voltdb,ingted/voltdb,kobronson/cs-voltdb,migue/voltdb,VoltDB/voltdb,simonzhangsm/voltdb,ingted/voltdb,kumarrus/voltdb,simonzhangsm/voltdb,wolffcm/voltdb,creative-quant/voltdb,kobronson/cs-voltdb,simonzhangsm/voltdb,deerwalk/voltdb,kobronson/cs-voltdb,kumarrus/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,creative-quant/voltdb,kumarrus/voltdb,paulmartel/voltdb,zuowang/voltdb,zuowang/voltdb,paulmartel/voltdb,flybird119/voltdb,kumarrus/voltdb,wolffcm/voltdb,creative-quant/voltdb,deerwalk/voltdb,creative-quant/voltdb,kumarrus/voltdb,kobronson/cs-voltdb,VoltDB/voltdb,migue/voltdb,flybird119/voltdb,migue/voltdb,ingted/voltdb,wolffcm/voltdb,kumarrus/voltdb,zuowang/voltdb,kobronson/cs-voltdb,wolffcm/voltdb,paulmartel/voltdb,wolffcm/voltdb,creative-quant/voltdb,VoltDB/voltdb,zuowang/voltdb,flybird119/voltdb,deerwalk/voltdb,kobronson/cs-voltdb,migue/voltdb,paulmartel/voltdb,migue/voltdb,wolffcm/voltdb,zuowang/voltdb,creative-quant/voltdb,simonzhangsm/voltdb,paulmartel/voltdb,zuowang/voltdb,wolffcm/voltdb,flybird119/voltdb,ingted/voltdb,ingted/voltdb,flybird119/voltdb,ingted/voltdb,wolffcm/voltdb,migue/voltdb,paulmartel/voltdb,migue/voltdb,kumarrus/voltdb,flybird119/voltdb,creative-quant/voltdb