Fix checkpoint's exiting semantics.
Fix checkpoint's exiting semantics.

Previously, dockerd would always ask containerd to pass --leave-running
to runc/runsc, ignoring the exit boolean value. Hence, even `docker
checkpoint create --leave-running=false ...` would not stop the
container.

Signed-off-by: Brielle Broder <bea399dcfd8ae64ea9edc37cc16c93a1bbe6c972@google.com>

tmp6154/docker,laijs/docker,konstruktoid/docker-upstream,pradipd/moby,jthelin/docker,docker/docker,moul/docker,SvenDowideit/docker,yongtang/docker,jameszhan/docker,Mokolea/docker,kojiromike/docker,dims/docker,kolyshkin/docker,kojiromike/docker,unclejack/docker,scotttlin/docker,gnailuy/docker,yongtang/docker,laijs/moby,nawawi/docker,djs55/docker,nawawi/docker,kolyshkin/moby,laijs/moby,justincormack/docker,x1022as/docker,jlhawn/docker,YuPengZTE/docker,rancher/docker,YuPengZTE/docker,docker/docker,cpuguy83/docker,justincormack/docker,flavio/docker,yongtang/docker,tmp6154/docker,gnailuy/docker,mahak/docker,nalind/docker,KarthikNayak/docker,kolyshkin/moby,jwhonce/docker,AkihiroSuda/docker,nawawi/docker,kolyshkin/docker,nalind/docker,ibuildthecloud/docker,AkihiroSuda/docker,rremer/moby,SvenDowideit/docker,x1022as/docker,pradipd/moby,thaJeztah/docker,tmp6154/docker,YuPengZTE/docker,djs55/docker,x1022as/docker,jameszhan/docker,cpuguy83/docker,konstruktoid/docker-1,moby/moby,jimjag/docker,unclejack/docker,flavio/docker,dmcgowan/docker,KarthikNayak/docker,mahak/docker,jwhonce/docker,cpuguy83/docker,Ramzec/docker,jvanz/docker,moul/docker,jameszhan/docker,vdemeester/docker,jimjag/docker,nalind/docker,AkihiroSuda/docker,paralin/docker,rancher/docker,konstruktoid/docker-1,gnailuy/docker,mikebrow/docker,thaJeztah/docker,laijs/docker,docker/docker,thaJeztah/docker,yosifkit/docker,moby/moby,jvanz/docker,jvanz/docker,nawawi/docker,scotttlin/docker,Ramzec/docker,Ramzec/docker,trebonian/docker,mikebrow/docker,nalind/docker,scotttlin/docker,pradipd/moby,paralin/docker,trebonian/docker,vdemeester/docker,moby/moby,unclejack/docker,ibuildthecloud/docker,estesp/docker,jthelin/docker,maxamillion/docker,trebonian/docker,allencloud/docker,bearstech/moby,maxamillion/docker,trebonian/docker,jwhonce/docker,AkihiroSuda/docker,konstruktoid/docker-upstream,dims/docker,flavio/docker,rremer/moby,mahak/docker,allencloud/docker,SvenDowideit/docker,estesp/docker,justincormack/docker,laijs/moby,Mokolea/docker,moul/docker,KarthikNayak/docker,vdemeester/docker,paralin/docker,jlhawn/docker,laijs/docker,crosbymichael/docker,cpuguy83/docker,yosifkit/docker,kolyshkin/moby,Ramzec/docker,jimjag/docker,bearstech/moby,paralin/docker,rremer/moby,konstruktoid/docker-upstream,Mokolea/docker,moby/moby,ibuildthecloud/docker,crosbymichael/docker,jlhawn/docker,estesp/docker,djs55/docker,maxamillion/docker,jimjag/docker,gnailuy/docker,yosifkit/docker,bearstech/moby,bearstech/moby,dims/docker,moul/docker,kojiromike/docker,rancher/docker,Mokolea/docker,ibuildthecloud/docker,mahak/docker,konstruktoid/docker-1,thaJeztah/docker,dmcgowan/docker,ibuildthecloud/docker,dmcgowan/docker,crosbymichael/docker,allencloud/docker,konstruktoid/docker-upstream,mikebrow/docker,flavio/docker,yosifkit/docker