cppcheck plugin variables patch

[virtuosonic]

Hi, cppcheck plugin isn't expanding variables for include dirs this patch fixes it

[killerbot]

good work, I will apply this :-)

[virtuosonic]

thanks

[killerbot]

applied it yesterday, but today had to patch it. Could lead to a crash. Fyi : virtual targets --> target will be a 0-pointer. So this needed to be protected.