restore: avoid an unterminated string

>>>     CID 164715:    (BUFFER_SIZE_WARNING)
>>>     Calling strncpy with a maximum size argument of 16 bytes on
	destination array "thread_args[i].comm" of size 16 bytes might
	leave the destination string unterminated.
3473    strncpy(thread_args[i].comm, core->tc->comm, TASK_COMM_LEN);

Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>