I got some useful leads on your issue by googling for this search term:
patching file include/uapi/linux/videodev2.h Hunk #1 FAILED at 624.
since this is the point where the installation process apparently goes wrong.
A number of people have experienced this HUNK #1 issue related to videodev2.h. There were not many helpful answers to be found though. The most potentially useful ones I found were:
ubuntu-mainline Hunk #1 FAILED · Issue #119 · IntelRealSense/librealsense · GitHub (the very last comment at the bottom of the page looks particularly interesting)
Thanks Marty! I have also found these two threads but still cannot solve it. I will keep trying.