At least one file in the DRM drivers benefits from some namespace pollution to use `fs_reclaim_acquire()`/`fs_reclaim_release()`. They are defined in `linux/sched/mm.h` and this header must be included indirectly into the DRM drivers' source file.
I couldn't find how it was included. Therefore this commit includes `linux/sched/mm.h` from `linux/sched.h`. This is not the case in Linux but fixes the issue with the DRM drivers.