crtools: update the usage message for log level
crtools: update the usage message for log level

We have more than 2 levels right now, update the usage message.

Signed-off-by: Huang Qiang <488e06933c295c76472a67dbc6657ac40a756953@huawei.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

LK4D4/criu,gablg1/criu,ldu4/criu,sdgdsffdsfff/criu,kawamuray/criu,biddyweb/criu,svloyso/criu,biddyweb/criu,kawamuray/criu,ldu4/criu,fbocharov/criu,KKoukiou/criu-remote,sdgdsffdsfff/criu,gonkulator/criu,svloyso/criu,biddyweb/criu,AuthenticEshkinKot/criu,fbocharov/criu,gablg1/criu,sdgdsffdsfff/criu,efiop/criu,marcosnils/criu,gablg1/criu,gonkulator/criu,tych0/criu,svloyso/criu,AuthenticEshkinKot/criu,ldu4/criu,tych0/criu,AuthenticEshkinKot/criu,marcosnils/criu,AuthenticEshkinKot/criu,gonkulator/criu,rentzsch/criu,rentzsch/criu,marcosnils/criu,efiop/criu,tych0/criu,tych0/criu,efiop/criu,rentzsch/criu,wtf42/criu,gablg1/criu,marcosnils/criu,wtf42/criu,eabatalov/criu,ldu4/criu,KKoukiou/criu-remote,eabatalov/criu,kawamuray/criu,svloyso/criu,gablg1/criu,ldu4/criu,fbocharov/criu,eabatalov/criu,wtf42/criu,efiop/criu,LK4D4/criu,LK4D4/criu,rentzsch/criu,eabatalov/criu,wtf42/criu,kawamuray/criu,sdgdsffdsfff/criu,tych0/criu,gonkulator/criu,gablg1/criu,eabatalov/criu,biddyweb/criu,KKoukiou/criu-remote,kawamuray/criu,AuthenticEshkinKot/criu,LK4D4/criu,KKoukiou/criu-remote,fbocharov/criu,ldu4/criu,AuthenticEshkinKot/criu,rentzsch/criu,marcosnils/criu,biddyweb/criu,tych0/criu,sdgdsffdsfff/criu,wtf42/criu,KKoukiou/criu-remote,gonkulator/criu,svloyso/criu,fbocharov/criu,wtf42/criu,eabatalov/criu,efiop/criu,fbocharov/criu,marcosnils/criu,kawamuray/criu,gonkulator/criu,biddyweb/criu,svloyso/criu,efiop/criu,sdgdsffdsfff/criu,rentzsch/criu,LK4D4/criu,KKoukiou/criu-remote,LK4D4/criu