Fix build error on centos6
Fix build error on centos6

Signed-off-by: Ye Yin <bf72484c12f335c7df3a34dc10be3d4958087681@qq.com>

maxamillion/runc,crosbymichael/runc,stefanberger/runc,rajasec/runc,wking/runc,coolljt0725/runc,wangkirin/runc,estesp/runc,albertoleal/runc,WeiZhang555/runc,ZJU-SEL/runc,adrianreber/runc,mheon/runc,coolljt0725/runc,estesp/runc,adrianreber/runc,kolyshkin/runc,jhowardmsft/runc,jhowardmsft/runc,nkwilson/runc,cloudfoundry-incubator/runc,sunyuan3/runc,kolyshkin/runc,xiaochenshen/runc,dqminh/runc,WeiZhang555/runc,shishir-a412ed/runc,abduld/runc,wangkirin/runc,nkwilson/runc,nkwilson/runc,crosbymichael/runc,hqhq/runc,adrianreber/runc,runcom/runc,docker/runc,sunyuan3/runc,avagin/runc,justincormack/runc,vbatts/runc,wangkirin/runc,opencontainers/runc,rhatdan/runc,crosbymichael/runc,kolyshkin/runc,rajasec/runc,albertoleal/runc,inatatsu/runc,justincormack/runc,maxamillion/runc,mheon/runc,dqminh/runc,runcom/runc,opencontainers/runc,abduld/runc,laijs/runc,mikebrow/runc,docker/runc,rhatdan/runc,laijs/runc,docker/runc,mheon/runc,wking/runc,rajasec/runc,mikebrow/runc,inatatsu/runc,xiaochenshen/runc,avagin/runc,keloyang/runc,keloyang/runc,mikebrow/runc,mYmNeo/runc,vbatts/runc,keloyang/runc,opencontainers/runc,WeiZhang555/runc,laijs/runc,shishir-a412ed/runc,avagin/runc,abduld/runc,xiaochenshen/runc,justincormack/runc,hqhq/runc,dqminh/runc,kolyshkin/runc,sunyuan3/runc,mYmNeo/runc,inatatsu/runc,ZJU-SEL/runc,cyphar/runc,mYmNeo/runc,shishir-a412ed/runc,albertoleal/runc,cloudfoundry-incubator/runc,maxamillion/runc,hqhq/runc,rhatdan/runc,rhatdan/runc,stefanberger/runc,opencontainers/runc,runcom/runc,dqminh/runc,vbatts/runc,jhowardmsft/runc,estesp/runc,cyphar/runc,cloudfoundry-incubator/runc,stefanberger/runc,cyphar/runc,wking/runc,ZJU-SEL/runc,coolljt0725/runc