dump: Check for regfile path being accessible
dump: Check for regfile path being accessible

A file pointed by an fd should be not unlinked
and be open-able with the provided path (overmounts
and/or renames coupled with links can screw it up).

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

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