/usr/src/linux-headers-4.8.0-45/zfs/include/sys/ is in linux-headers-4.8.0-45 4.8.0-45.48~16.04.1.
This file is owned by root:root, with mode 0o755.
..
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/Makefile.am
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/Makefile.in
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/Makefile.am
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/Makefile.in
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/fs/
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/fs/Makefile.am
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fm/fs/Makefile.in
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fs/
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fs/Makefile.am
/usr/src/linux-headers-4.8.0-45/zfs/include/sys/fs/Makefile.in