zdtm: fix msg reporting

avoid err() for regular msg reporting

Acked-by: Andrew Vagin <avagin@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
service: service should compile on Ubuntu 14.04

I'm not quite sure what the difference is (I have gcc 4.8, but there are
probably also header differences), but when I compile the service on 14.04 I
get:

  CC       cr-service.o
cr-service.c: In function ‘start_page_server_req’:
cr-service.c:536:8: error: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Werror=unused-result]
   write(start_pipe[1], &ret, sizeof(ret));
        ^
cr-service.c:544:6: error: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Werror=unused-result]
  read(start_pipe[0], &ret, sizeof(ret));
      ^

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Tested-by: https://travis-ci.org/avagin/criu/builds/34990769
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
security: change CR_FD_PERM from rw-rw-r-- to rw-r--r--

This makes only root to be able to modify images by default.
When using criu with suid bit set, group of the images is set
to user group, which is not safe, considering current CR_FD_PERM.
But, if root decides to change imgs mode, criu will restore
those images, if they are not contradicting any other security
rules.

Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>