daemon: un-export VerifyCgroupDriver()
daemon: un-export VerifyCgroupDriver()

it's only used internally, so no need to export

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

thaJeztah/docker,Mokolea/docker,djs55/docker,moul/docker,flavio/docker,mahak/docker,cpuguy83/docker,moby/moby,konstruktoid/docker-upstream,thaJeztah/docker,moul/docker,konstruktoid/docker-upstream,djs55/docker,vdemeester/docker,trebonian/docker,nawawi/docker,Mokolea/docker,konstruktoid/docker-upstream,bearstech/moby,AkihiroSuda/docker,paralin/docker,moul/docker,moby/moby,paralin/docker,Ramzec/docker,cpuguy83/docker,yosifkit/docker,vdemeester/docker,jameszhan/docker,trebonian/docker,jimjag/docker,jameszhan/docker,trebonian/docker,AkihiroSuda/docker,cpuguy83/docker,nawawi/docker,nalind/docker,nalind/docker,mahak/docker,flavio/docker,gnailuy/docker,konstruktoid/docker-upstream,jameszhan/docker,nawawi/docker,jimjag/docker,jthelin/docker,moby/moby,paralin/docker,gnailuy/docker,cpuguy83/docker,nalind/docker,Mokolea/docker,Ramzec/docker,moul/docker,docker/docker,bearstech/moby,jimjag/docker,AkihiroSuda/docker,gnailuy/docker,Ramzec/docker,flavio/docker,Mokolea/docker,vdemeester/docker,thaJeztah/docker,nawawi/docker,mahak/docker,yosifkit/docker,djs55/docker,docker/docker,thaJeztah/docker,bearstech/moby,trebonian/docker,yosifkit/docker,paralin/docker,nalind/docker,flavio/docker,bearstech/moby,moby/moby,Ramzec/docker,yosifkit/docker,jimjag/docker,jthelin/docker,docker/docker,AkihiroSuda/docker,gnailuy/docker,mahak/docker