linuxkpi: Define lockdep_assert_none_held_once()

This is defined as a no-op even when INVARIANTS is defined. I admit I
don't know how to implement that in FreeBSD and didn't search
thoroughly.

Reviewed by: bz
Approved by: bz
Differential Revision: https://reviews.freebsd.org/D37911

(cherry picked from commit 17f2b12a3877f460f72123242c068881806388c2)