This way it is more easily accessed from drivers outside the kernel,
which it soon will be, without having to add an explicit UseHeaders.
(The drivers that use it already all use the IOScheduler.)
No functional change.
Change-Id: Ibc2d2678e37d9d7ab73391cb17b72cca86f92132
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6477
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: waddlesplash <[email protected]>