Fix a race condition that occurs in parallel builds of
nvidia-settings, frequently ending in the following error:
/bin/bash: _out/Linux_x86_64/antialias.png.h: No such file or directory
make[1]: *** [Makefile:320: _out/Linux_x86_64/antialias.png.h] Error 1
Upstream issue and fix from:
https://github.com/NVIDIA/nvidia-settings/issues/59
Daniël de Kok