correctly install signal handler for lxc-init
correctly install signal handler for lxc-init

This patch is to correct the manipulation of signal masks when
installing signal handlers for lxc-init. 

Signed-off-by: Jian Xiao <fc960ba2fee6912432701eda240a83bcb44b43ae@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <21a0ac3a0184cbb5f322585bd41886b0e67aa0d7@fr.ibm.com>
Signed-off-by: Daniel Lezcano <3211518dd4d87cb3f7ee12cb52e14b7fb2bc0446@fr.ibm.com>

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