To test if we can survive with shmid more than 4 bytes
long in image formats.

Without the fix for shmid

 | [root@uranus criu] test/zdtm.py run -t zdtm/static/maps01 --fault 132 -f h -k always
 | === Run 1/1 ================ zdtm/static/maps01
 |
 | ========================= Run zdtm/static/maps01 in h ==========================
 | Start test
 | Test is SUID
 | ./maps01 --pidfile=maps01.pid --outfile=maps01.out
 | Run criu dump
 | Forcing 132 fault
 | Run criu restore
 | Forcing 132 fault
 | =[log]=> dump/zdtm/static/maps01/36/1/restore.log
 | ------------------------ grep Error ------------------------
 | (00.016464)     37: Opening 0x007f39c04b5000-0x007f3a004b5000 0000000000000000 (101) vma
 | (00.016465)     37: Search for 0x007f39c04b5000 shmem 0x10118e915 0x7f97f7ae4ae8/36
 | (00.016470)     37: Waiting for the 10118e915 shmem to appear
 | (00.016479)     36: No pagemap-shmem-18409749.img image
 | (00.016481)     36: Error (criu/shmem.c:559): Can't restore shmem content
 | (00.016501)     36: Error (criu/mem.c:1208): `- Can't open vma
 | (00.016552) Error (criu/cr-restore.c:2449): Restoring FAILED.
 | ------------------------ ERROR OVER ------------------------

And with the fix

 | [root@uranus criu] test/zdtm.py run -t zdtm/static/maps01 --fault 132 -f h -k always
 | === Run 1/1 ================ zdtm/static/maps01
 |
 | ========================= Run zdtm/static/maps01 in h ==========================
 | Start test
 | Test is SUID
 | ./maps01 --pidfile=maps01.pid --outfile=maps01.out
 | Run criu dump
 | Forcing 132 fault
 | Run criu restore
 | Forcing 132 fault
 | Send the 15 signal to  36
 | Wait for zdtm/static/maps01(36) to die for 0.100000
 | ========================= Test zdtm/static/maps01 PASS =========================
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>