greenboost.c: code calls non-existent function, build fails as result

[oaf40]

greenboost.c, line 970, introduced in commit f8a70e3:
dma_buf_set_priority(dmabuf, 200);

This function isn't defined anywhere. Neither in greenboost project, nor in the kernel headers.
DKMS cannot build greenboost.c, most likely all commits since f8a70e3 are affected.