seize: fix memory corruption

277                     }
>>> >>>     CID 164718:  Memory - corruptions  (OVERRUN)
>>> >>>     Overrunning array "stackbuf" of 2048 bytes at byte offset 2048 using index "ret" (which evaluates to 2048).
278                     stackbuf[ret] = '\0';
Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/seize.c

@@ -270,7 +270,7 @@ static int log_unfrozen_stacks(char *root)
 			return -1;
 		}
 
-		ret = read(stack, stackbuf, sizeof(stackbuf));
+		ret = read(stack, stackbuf, sizeof(stackbuf) - 1);
 		close(stack);
 		if (ret < 0) {
 			pr_perror("couldn't read %d's stack", pid);