Hi,
I had the same issue, this is how I fixed it:
Inside the unpacked mft folder
mkdir tmp
dpkg-deb -R SDEBS/kernel-mft-dkms_4.22.1-11_all.deb tmp
# Add ../../nnt_driver/ in front of the nnt_ includes
# Example: #include "../../nnt_driver/nnt_ioctl.h"
nano...