wal: minor typo in wal pkg
wal: minor typo in wal pkg

Fixes a minor typo in wal.go.
Thanks!

etcd-io/etcd,dannysauer/etcd,joshix/etcd,qqsun8819/etcd,tamird/etcd,mkumatag/etcd,mqliang/etcd,jlamillan/etcd,vimalk78/etcd,yudai/etcd,mqliang/etcd,bdarnell/etcd,chipironcin/etcd,shawnps/etcd,CrazyJvm/etcd,tguangch/etcd,hongchaodeng/etcd,plasticbox/etcd,whuwxl/etcd,sayden/etcd,achanda/etcd,bluebreezecf/etcd,oscarrr110/etcd,cchamplin/etcd,zaphod-concur/etcd,glevand/coreos--etcd,swingbach/etcd,qqsun8819/etcd,glycerine/etcd,cockroachdb/etcd,sofuture/etcd,plasticbox/etcd,sebrandon1/etcd,wantonsolutions/dinv-etcd,mickep76/etcd,fasaxc/etcd,purpleidea/etcd,rchicoli/etcd,fanminshi/etcd,rnaveiras/etcd,ktateish/etcd,insequent/etcd,joshix/etcd,purpleidea/etcd,mkumatag/etcd,raoofm/etcd,akauppi/etcd,endocode/etcd,linuxcer/etcd,fasaxc/etcd,cchamplin/etcd,gyuho/etcd,vimalk78/etcd,mkumatag/etcd,visheshnp/etcd,a-robinson/etcd,rchicoli/etcd,luxas/etcd,sebrandon1/etcd,Timer/etcd,siddontang/etcd,sofuture/etcd,xiang90/etcd,sinsharat/etcd,akauppi/etcd,sayden/etcd,whuwxl/etcd,raoofm/etcd,coreos/etcd,westhood/etcd,jonboulle/etcd,ajityagaty/etcd,YuleiXiao/etcd,etcd-io/etcd,a-robinson/etcd,lumjjb/etcd,gyuho/etcd,CrazyJvm/etcd,fanminshi/etcd,siddontang/etcd,oscarrr110/etcd,yudai/etcd,li-ang/etcd,fasaxc/etcd,Timer/etcd,HideoYamauchi/etcd,insequent/etcd,tguangch/etcd,chipironcin/etcd,OyTao/etcd_learning,mqliang/etcd,zaphod-concur/etcd,achanda/etcd,wantonsolutions/dinv-etcd,wantonsolutions/dinv-etcd,ravigadde/etcd,StorReduce/etcd,jlamillan/etcd,OyTao/etcd_learning,mickep76/etcd,glycerine/etcd,hongchaodeng/etcd,armstrongli/etcd,bluebreezecf/etcd,visheshnp/etcd,heyitsanthony/etcd,jonboulle/etcd,StorReduce/etcd,xiang90/etcd,shawnps/etcd,sinsharat/etcd,li-ang/etcd,swingbach/etcd,endocode/etcd,westhood/etcd,bdarnell/etcd,heyitsanthony/etcd,rnaveiras/etcd,nekto0n/etcd,YuleiXiao/etcd,etcd-io/etcd,linuxcer/etcd,HideoYamauchi/etcd,handsomesun/etcd,tamird/etcd,handsomesun/etcd,rnaveiras/etcd,lumjjb/etcd,ktateish/etcd,luxas/etcd,ajityagaty/etcd,glevand/coreos--etcd,cockroachdb/etcd,nekto0n/etcd,ajityagaty/etcd,dannysauer/etcd,dnaeon/etcd,lorneli/etcd,armstrongli/etcd,dnaeon/etcd,coreos/etcd,lorneli/etcd,ravigadde/etcd