give a hint if old cgroup can't be moved
give a hint if old cgroup can't be moved

When cgroup can't be moved, it might be a hint container is already
running.

Signed-off-by: Serge Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>

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