tools/getdelays: use the static UAPI headers from tools/include/uapi

The include directory ../../usr/include is only present if an in-tree
kernel build with CONFIG_HEADERS_INSTALL was done before.
Otherwise the system UAPI headers are used, which most likely are not
the most recent ones.

To make sure to always have access to up-to-date UAPI headers,
use the static copy in tools/include/uapi.

Link: https://lkml.kernel.org/r/20260307-accounting-taskstats-h-v1-2-0b75915c6ce5@weissschuh.net
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202603062103.Z5fecwZD-lkp@intel.com/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Jiang Kun <jiang.kun2@zte.com.cn>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>