The documentation says this:
"In order to build LUFS you need to have the running kernel's headers installed. Check whether /lib/modules/`uname - r`/build/include is pointing to the right place."
How to I check that what is pointing to where? :)
The configure script will do the check for you.
Shortly, it translates to these 2 conditions:
1 - you must have your runnig kernel's source (headers)
2 - your runnig kernel must be installed from that tree ( equivalent to /lib/modules/`uname -r`/build link pointing to the source tree)