scripts: return non zero if save_mountpoint() fails
scripts: return non zero if save_mountpoint() fails

In such case, we must not proceed: without saved mountpoint, we risk
losing data when restarting automount service (think about tmpfs).
Currently, zero will be returned as exit status of preceeding echo.
https://jira.sw.ru/browse/PSBM-44207

Signed-off-by: Eugene Kolomeetz <e13ac15a30aaa8c841b369b1e0ca4d4d79ffd8cf@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@virtuozzo.com>

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