lxc_spawn: don't close pinfd until container is stopped
lxc_spawn: don't close pinfd until container is stopped

Otherwise containers may be able to remount -o ro their rootfs
at shutdown.

Reported-by: Harald Dunkel <9ca526290289c02cc3751af53e398ecf4d4c27e5@afaics.de>
Signed-off-by: Serge Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>
Acked-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

armcc/lxc,ysbnim/lxc,Distrotech/lxc,GreatFruitOmsk/lxc,cjwatson/lxc,federicobriata/lxc,thmo/lxc,glensc/lxc,armcc/lxc,virajs/lxc,LynxChaus/lxc,DarknessBeforeDawn/lxc,cjwatson/lxc,weizhenwei/lxc,bmoar/lxc,rldleblanc/lxc,Pelagicore/lxc,aeris/lxc,yubo/lxc,federicobriata/lxc,terceiro/lxc,Pelagicore/lxc,fwilson42/lxc,bmoar/lxc,ojkastl/lxc_Patches,hkjolhede/lxc,DarknessBeforeDawn/lxc,christiaan/lxc,ss1h2a3tw/lxc,bostjan/lxc,LynxChaus/lxc,lazy404/lxc,szaszg/lxc,ecarrara/lxc,efiop/lxc,hkjolhede/lxc,terceiro/lxc,rowhit/lxc,akshaykarle/lxc,hallyn/lxc,bmoar/lxc,bostjan/lxc,QingweiPeterLan/cs188-lxc,ysbnim/lxc,jirislaby/lxc,sapun/lxc,ss1h2a3tw/lxc,ecarrara/lxc,JohnPeacockMessageSystems/lxc,bostjan/lxc,hfuCN/lxc,lisongmin/lxc,aeris/lxc,lazy404/lxc,Ponce/lxc,caglar10ur/lxc,ioops/lxc,caglar10ur/lxc,christiaan/lxc,tych0/lxc,virajs/lxc,JohnPeacockMessageSystems/lxc,ojkastl/lxc_Patches,hkjolhede/lxc,Pelagicore/lxc,ss1h2a3tw/lxc,Distrotech/lxc,hfuCN/lxc,akshaykarle/lxc,tych0/lxc,lisongmin/lxc,QingweiPeterLan/cs188-lxc,glensc/lxc,ojkastl/lxc_Patches,ioops/lxc,ksperis/lxc,Distrotech/lxc,terceiro/lxc,raspberrypython/lxc,hallyn/lxc,tych0/lxc,virajs/lxc,weizhenwei/lxc,Ponce/lxc,JohnPeacockMessageSystems/lxc,ysbnim/lxc,raspberrypython/lxc,DarknessBeforeDawn/lxc,cjwatson/lxc,rldleblanc/lxc,jirislaby/lxc,yubo/lxc,ioops/lxc,major/lxc,rldleblanc/lxc,raspberrypython/lxc,major/lxc,federicobriata/lxc,szaszg/lxc,codebauss/lxc,weizhenwei/lxc,akshaykarle/lxc,yubo/lxc,GreatFruitOmsk/lxc,jirislaby/lxc,QingweiPeterLan/cs188-lxc,thmo/lxc,fwilson42/lxc,codebauss/lxc,aeris/lxc,ksperis/lxc,glensc/lxc,codebauss/lxc,caglar10ur/lxc,ecarrara/lxc,rowhit/lxc,regit/lxc,rowhit/lxc,sapun/lxc,szaszg/lxc,ojkastl/lxc_Patches,regit/lxc,lisongmin/lxc,LynxChaus/lxc,thmo/lxc,regit/lxc,sapun/lxc,GreatFruitOmsk/lxc,armcc/lxc,fwilson42/lxc,Ponce/lxc,major/lxc,hfuCN/lxc,hallyn/lxc,efiop/lxc,efiop/lxc,lazy404/lxc,christiaan/lxc,ksperis/lxc