Use rslave instead of rprivate in chrootarchive
Use rslave instead of rprivate in chrootarchive

With `rprivate` there exists a race where a reference to a mount has
propagated to the new namespace, when `rprivate` is set the parent
namespace is not able to remove the mount due to that reference.
With `rslave` unmounts will propagate correctly into the namespace and
prevent the sort of transient errors that are possible with `rprivate`.

This is a similar fix to https://github.com/opencontainers/runc/pull/1500/commits/117c92745bd098bf05a69489b7b78cac6364e1d0

Signed-off-by: Brian Goff <dc73d0991b982a8303e713ef531a313af77e242a@gmail.com>

ripcurld0/moby,rremer/moby,Ramzec/docker,bearstech/moby,shishir-a412ed/docker,dims/docker,SvenDowideit/docker,justincormack/docker,miminar/docker,nalind/docker,yosifkit/docker,tmp6154/docker,laijs/moby,dmcgowan/docker,gnailuy/docker,tophj-ibm/docker,madhanrm/docker,rancher/docker,yosifkit/docker,PatrickLang/moby,unclejack/docker,whuwxl/docker,thaJeztah/docker,docker/docker,moul/docker,ibuildthecloud/docker,laijs/docker,YuPengZTE/docker,gnailuy/docker,ibuildthecloud/docker,dims/docker,Mokolea/docker,laijs/docker,ibuildthecloud/docker,jameszhan/docker,KingEmet/docker,Mokolea/docker,tonistiigi/docker,yummypeng/docker,paralin/docker,Ramzec/docker,srust/docker,rhatdan/docker,flavio/docker,rancher/docker,yongtang/docker,konstruktoid/docker-upstream,nalind/docker,srust/docker,laijs/moby,AkihiroSuda/docker,dccurtis/docker,moul/docker,srust/docker,nawawi/docker,mahak/docker,mahak/docker,cyphar/docker,tophj-ibm/docker,tmp6154/docker,KingEmet/docker,vdemeester/docker,mikebrow/docker,cyphar/docker,cyphar/docker,AkihiroSuda/docker,whuwxl/docker,crosbymichael/docker,kojiromike/docker,kolyshkin/moby,AkihiroSuda/docker,yongtang/docker,unclejack/docker,allencloud/docker,jvanz/docker,djs55/docker,jameszhan/docker,Ramzec/docker,johnstep/moby-moby,konstruktoid/docker-1,jwhonce/docker,jlhawn/docker,x1022as/docker,madhanrm/docker,jlhawn/docker,unclejack/docker,scotttlin/docker,x1022as/docker,pradipd/moby,konstruktoid/docker-upstream,paralin/docker,tonistiigi/docker,yummypeng/docker,trebonian/docker,tophj-ibm/docker,crosbymichael/docker,KarthikNayak/docker,rremer/moby,kolyshkin/moby,duglin/docker,jthelin/docker,crosbymichael/docker,jimjag/docker,nawawi/docker,vdemeester/docker,thaJeztah/docker,estesp/docker,jlhawn/docker,AkihiroSuda/docker,konstruktoid/docker-1,noironetworks/docker,KarthikNayak/docker,dmcgowan/docker,tophj-ibm/moby,johnstep/moby-moby,jimjag/docker,nawawi/docker,nalind/docker,docker/docker,mikebrow/docker,SvenDowideit/docker,duglin/docker,YuPengZTE/docker,PatrickLang/moby,ndeloof/docker,trebonian/docker,kojiromike/docker,thaJeztah/docker,jimjag/docker,konstruktoid/docker-upstream,yosifkit/docker,kojiromike/docker,moby/moby,Mokolea/docker,dccurtis/docker,miminar/docker,justincormack/docker,tophj-ibm/moby,laijs/moby,x1022as/docker,rhatdan/docker,laijs/docker,jwhonce/docker,konstruktoid/docker-upstream,bearstech/moby,thaJeztah/docker,nalind/docker,maxamillion/docker,ibuildthecloud/docker,jvanz/docker,mixja/docker,moby/moby,kolyshkin/moby,yongtang/docker,ndeloof/docker,madhanrm/docker,miminar/docker,shishir-a412ed/docker,paralin/docker,SvenDowideit/docker,ripcurld0/moby,djs55/docker,shishir-a412ed/docker,bearstech/moby,jameszhan/docker,yosifkit/docker,flavio/docker,moul/docker,Ramzec/docker,allencloud/docker,KingEmet/docker,nawawi/docker,mahak/docker,scotttlin/docker,yummypeng/docker,cpuguy83/docker,Mokolea/docker,jimjag/docker,ndeloof/docker,rancher/docker,whuwxl/docker,moby/moby,cpuguy83/docker,kolyshkin/docker,allencloud/docker,rremer/moby,trebonian/docker,flavio/docker,pradipd/moby,KarthikNayak/docker,konstruktoid/docker-1,paralin/docker,noironetworks/docker,ibuildthecloud/docker,ripcurld0/moby,docker/docker,kolyshkin/docker,mixja/docker,djs55/docker,cpuguy83/docker,vdemeester/docker,duglin/docker,gnailuy/docker,johnstep/moby-moby,scotttlin/docker,tmp6154/docker,bearstech/moby,YuPengZTE/docker,pradipd/moby,noironetworks/docker,jthelin/docker,estesp/docker,jwhonce/docker,flavio/docker,rhatdan/docker,dmcgowan/docker,mixja/docker,mahak/docker,jvanz/docker,maxamillion/docker,gnailuy/docker,mikebrow/docker,estesp/docker,PatrickLang/moby,maxamillion/docker,moul/docker,dccurtis/docker,moby/moby,tonistiigi/docker,cpuguy83/docker,justincormack/docker,tophj-ibm/moby,trebonian/docker,dims/docker