Problem with compilation prevents me from adding a new device

[Dominik Danelski <dominik@danelski.pl>]

Hello,

I found this 
guide:https://www.onetransistor.eu/2017/05/magix-usb-videowandler-2-linux.html 
which explains how to get Magix Videowandler 2 as an audio-video 
source. It is achieved by downloading drivers from LinuxTV project, 
slightly modifying them and installing. I wanted to incorporate changes 
from the guide to the upstream code, but first I wanted to test 
everything once again. I tried to follow the described method of 
compiling drivers (before making any changes) and I got stuck with a 
following output:
  CC [M]  /tmp/media_build/v4l/videobuf-core.o
  CC [M]  /tmp/media_build/v4l/videobuf-dma-sg.o
/tmp/media_build/v4l/videobuf-dma-sg.c: In function 
'videobuf_dma_init_user_locked':
/tmp/media_build/v4l/videobuf-dma-sg.c:190:17: error: 'FOLL_LONGTERM' 
undeclared (first use in this function); did you mean 'FOLL_FORCE'?
         flags | FOLL_LONGTERM, dma->pages, NULL);
                 ^~~~~~~~~~~~~
                 FOLL_FORCE
/tmp/media_build/v4l/videobuf-dma-sg.c:190:17: note: each undeclared 
identifier is reported only once for each function it appears in

What could have caused it? I suppose that the code already in the 
repository has been checked and such thing should not happen if not by 
my mistake, but I did not change anything after cloning git repo.

Regards
Dominik Danelski