There is another (modified?) patch available for the latest NVIDIA driver and Kernel 5.5-rc ( see the NVIDIA Forum article at https://devtalk.nvidia.com/default/topic/1068332/linux/nvidia-driver-does-not-build-on-linux-v5-5-release-candidate-kernel/ ).
I have applied this to driver 440.44 on Kernel 5.5-rc3, and it compiles OK, and loads/runs without the ‘tombstone’ that I experienced with previous versions.
Robert Gadsdon. December 24th 2019.