[Why]
Some files in DRM rely on this indirect include to use `struct rb_*`.
Reviewed by: manu
Approved by: manu
Differential Revision: https://reviews.freebsd.org/D42835
(cherry picked from commit b292c995cfa88cc73d5d77b6b94ae1b78296793f)
It is the same as callout_stop(9) but the return values are different.
Reviewed by: hselasky
Approved by: hselasky
Differential Revision: https://reviews.freebsd.org/D38081
While there, switch to FreeBSD internal callout active status.
Reviewed by: markj, hselasky
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D11900