I'm not sure if 4.4 had the same issue, but there is an issue with 6.x kernel dev files where the nfsfh.h file is incomplete or truncated, compared to a generic Linux equivalent.
This link may help point you in the direction on what to keep in mind for building...
https://www-secure.symantec.com/connect/forums/sav-savap-antivirus-centos-62