e2e: compare output in Go string literal
e2e: compare output in Go string literal

I manually print out the command outputs when the issue
was reproduced, and checked they are matching when compared as
Go string literals (UTF-8), but not when compared with regex.

Fixes https://github.com/coreos/etcd/issues/4480.

StorReduce/etcd,akauppi/etcd,glevand/coreos--etcd,tguangch/etcd,tguangch/etcd,nekto0n/etcd,chipironcin/etcd,zaphod-concur/etcd,siddontang/etcd,visheshnp/etcd,lumjjb/etcd,qqsun8819/etcd,joshix/etcd,plasticbox/etcd,sinsharat/etcd,YuleiXiao/etcd,glycerine/etcd,joshix/etcd,linuxcer/etcd,dnaeon/etcd,handsomesun/etcd,nekto0n/etcd,vimalk78/etcd,armstrongli/etcd,vimalk78/etcd,ajityagaty/etcd,chipironcin/etcd,sinsharat/etcd,xiang90/etcd,a-robinson/etcd,swingbach/etcd,zaphod-concur/etcd,rnaveiras/etcd,purpleidea/etcd,gyuho/etcd,insequent/etcd,mqliang/etcd,wantonsolutions/dinv-etcd,xiang90/etcd,achanda/etcd,jlamillan/etcd,rchicoli/etcd,lumjjb/etcd,mqliang/etcd,endocode/etcd,coreos/etcd,CrazyJvm/etcd,tamird/etcd,coreos/etcd,glevand/coreos--etcd,bdarnell/etcd,wantonsolutions/dinv-etcd,cockroachdb/etcd,akauppi/etcd,rnaveiras/etcd,qqsun8819/etcd,dannysauer/etcd,cockroachdb/etcd,etcd-io/etcd,ravigadde/etcd,visheshnp/etcd,yudai/etcd,mqliang/etcd,hongchaodeng/etcd,fanminshi/etcd,heyitsanthony/etcd,lorneli/etcd,sebrandon1/etcd,ajityagaty/etcd,armstrongli/etcd,hongchaodeng/etcd,a-robinson/etcd,ravigadde/etcd,mkumatag/etcd,mickep76/etcd,dnaeon/etcd,ajityagaty/etcd,mkumatag/etcd,li-ang/etcd,swingbach/etcd,lorneli/etcd,gyuho/etcd,bdarnell/etcd,heyitsanthony/etcd,dannysauer/etcd,sofuture/etcd,OyTao/etcd_learning,ktateish/etcd,glycerine/etcd,bluebreezecf/etcd,whuwxl/etcd,endocode/etcd,jlamillan/etcd,linuxcer/etcd,westhood/etcd,insequent/etcd,luxas/etcd,wantonsolutions/dinv-etcd,mkumatag/etcd,rnaveiras/etcd,rchicoli/etcd,sebrandon1/etcd,achanda/etcd,OyTao/etcd_learning,whuwxl/etcd,fanminshi/etcd,ktateish/etcd,westhood/etcd,bluebreezecf/etcd,purpleidea/etcd,YuleiXiao/etcd,siddontang/etcd,etcd-io/etcd,CrazyJvm/etcd,luxas/etcd,mickep76/etcd,handsomesun/etcd,StorReduce/etcd,sofuture/etcd,yudai/etcd,li-ang/etcd,tamird/etcd,jonboulle/etcd,jonboulle/etcd,plasticbox/etcd,etcd-io/etcd