state: improved upgradeSuite collection cleanup
state: improved upgradeSuite collection cleanup

Instead of returning closer functions, AddCleanup is used. This makes
the code more readable and avoids nasty errors regarding open MongoDB
sockets if an assertion fails before checkEnvUUID has returned.

bogdanteleaga/juju,tsakas/juju,bac/juju,kat-co/juju,ericsnowcurrently/juju,fwereade/juju,wwitzel3/juju,frankban/juju,bogdanteleaga/juju,Altoros/juju-cloudsigma,cmars/juju,frankban/juju-tmp,macgreagoir/juju,anastasiamac/juju,ericsnowcurrently/juju,AdamIsrael/juju,axw/juju,reedobrien/juju,macgreagoir/juju,Altoros/juju-vmware,reedobrien/juju,frankban/juju,reedobrien/juju,sinzui/juju,mhilton/juju-juju,Altoros/juju-cloudsigma,davecheney/juju,bz2/juju,mjs/juju,axw/juju,AdamIsrael/juju,marcoceppi/juju,howbazaar/juju,mhilton/juju,dooferlad/juju,marcmolla/juju,frankban/juju,tasdomas/juju,axw/juju,alesstimec/juju,cherylj/juju,davecheney/juju,mjs/juju,frankban/juju,makyo/juju,mjs/juju,mhilton/juju,howbazaar/juju,mjs/juju,wwitzel3/juju,tych0/juju,voidspace/juju,gabriel-samfira/juju,cherylj/juju,sinzui/juju,alesstimec/juju,bac/juju,sinzui/juju,ericsnowcurrently/juju,ericsnowcurrently/juju,marcmolla/juju,makyo/juju,makyo/juju,perrito666/juju,waigani/juju,thomnico/juju,voidspace/juju,cmars/juju,tsakas/juju,AdamIsrael/juju,mjs/juju,axw/juju,gabriel-samfira/juju,voidspace/juju,sinzui/juju,mhilton/juju-juju,cherylj/juju,dooferlad/juju,ericsnowcurrently/juju,macgreagoir/juju,dimitern/juju,kat-co/juju,Altoros/juju-cloudsigma,tych0/juju,Altoros/juju-cloudsigma,cloud-green/juju,tasdomas/juju,cloud-green/juju,alesstimec/juju,dimitern/juju,voidspace/juju,mikemccracken/juju,howbazaar/juju,mhilton/juju-juju,cmars/juju,bac/juju,mhilton/juju,macgreagoir/juju,mjs/juju,mikemccracken/juju,tych0/juju,cmars/juju,dooferlad/juju,bz2/juju,makyo/juju,mikemccracken/juju,bz2/juju,dimitern/juju,alesstimec/juju,macgreagoir/juju,gabriel-samfira/juju,mikemccracken/juju,fwereade/juju,kat-co/juju,wwitzel3/juju,axw/juju,frankban/juju-tmp,cloud-green/juju,mikemccracken/juju,mhilton/juju-juju,dooferlad/juju,marcoceppi/juju,marcmolla/juju,cloud-green/juju,tych0/juju,frankban/juju-tmp,frankban/juju,Altoros/juju-vmware,gabriel-samfira/juju,waigani/juju,perrito666/juju,Altoros/juju-vmware,bz2/juju,thomnico/juju,alesstimec/juju,anastasiamac/juju,anastasiamac/juju,waigani/juju,fwereade/juju,waigani/juju,kat-co/juju,marcoceppi/juju,thomnico/juju,kat-co/juju,AdamIsrael/juju,mhilton/juju,tasdomas/juju,howbazaar/juju,tsakas/juju,dooferlad/juju,bac/juju,wwitzel3/juju,reedobrien/juju,fwereade/juju,mjs/juju,davecheney/juju,marcmolla/juju,perrito666/juju,gabriel-samfira/juju,marcmolla/juju,dimitern/juju,reedobrien/juju,tsakas/juju,thomnico/juju,davecheney/juju,cherylj/juju,perrito666/juju,bz2/juju,anastasiamac/juju,bac/juju,dimitern/juju,bogdanteleaga/juju,marcoceppi/juju,frankban/juju-tmp,Altoros/juju-vmware,bogdanteleaga/juju,tasdomas/juju,anastasiamac/juju,howbazaar/juju,perrito666/juju