kmemcheck: rip it out for real

Commit 4675ff0 ("kmemcheck: rip it out") has removed the code but
for some reason SPDX header stayed in place.  This looks like a rebase
mistake in the mmotm tree or the merge mistake.  Let's drop those
leftovers as well.

Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Michal Hocko