pstree: Move the ids reading into separate function
pstree: Move the ids reading into separate function

It's just a cleanup to get rid of in-function {<code>} block.

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

efiop/criu,KKoukiou/criu-remote,AuthenticEshkinKot/criu,eabatalov/criu,eabatalov/criu,KKoukiou/criu-remote,KKoukiou/criu-remote,eabatalov/criu,KKoukiou/criu-remote,efiop/criu,AuthenticEshkinKot/criu,AuthenticEshkinKot/criu,eabatalov/criu,efiop/criu,AuthenticEshkinKot/criu,AuthenticEshkinKot/criu,KKoukiou/criu-remote,KKoukiou/criu-remote,efiop/criu,efiop/criu,AuthenticEshkinKot/criu,efiop/criu,eabatalov/criu,eabatalov/criu