zdtm: check restoring of sockets in the TCP_CLOSE state

(00.004456) Error (sk-inet.c:188): Name resolved on unconnected socket
(00.004466) Error (cr-dump.c:1255): Dump files (pid: 7944) failed with -1
(00.004680) Error (cr-dump.c:1617): Dumping FAILED.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>