zdtm.py: print an error message at the end if something failed
zdtm.py: print an error message at the end if something failed

Signed-off-by: Andrew Vagin <74c05afa918858348d6db8037d82fa8124870113@openvz.org>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

ldu4/criu,KKoukiou/criu-remote,fbocharov/criu,tych0/criu,fbocharov/criu,tych0/criu,KKoukiou/criu-remote,svloyso/criu,ldu4/criu,efiop/criu,AuthenticEshkinKot/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,efiop/criu,fbocharov/criu,wtf42/criu,tych0/criu,svloyso/criu,tych0/criu,tych0/criu,fbocharov/criu,AuthenticEshkinKot/criu,wtf42/criu,ldu4/criu,wtf42/criu,ldu4/criu,AuthenticEshkinKot/criu,ldu4/criu,wtf42/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,fbocharov/criu,efiop/criu,eabatalov/criu,svloyso/criu,AuthenticEshkinKot/criu,efiop/criu,efiop/criu,eabatalov/criu,eabatalov/criu,svloyso/criu,ldu4/criu,wtf42/criu,fbocharov/criu,eabatalov/criu,KKoukiou/criu-remote,efiop/criu,eabatalov/criu,svloyso/criu,KKoukiou/criu-remote,svloyso/criu,tych0/criu,eabatalov/criu,wtf42/criu