pidfs: add missing PIDFD_INFO_SIZE_VER1

pidfs: add missing PIDFD_INFO_SIZE_VER1

[ Upstream commit 4061c43a99772c66c378cfacaa71550ab3b35909 ]

We grew struct pidfd_info not too long ago.

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-3-ca449b7b7aa0@kernel.org
Fixes: 1d8db6fd698d ("pidfs, coredump: add PIDFD_INFO_COREDUMP")
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>