kmemcheck: rip it out for real

Commit 4675ff05 ("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 <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/include/asm/kmemcheck.h

-/* SPDX-License-Identifier: GPL-2.0 */

arch/x86/mm/kmemcheck/error.c

-// SPDX-License-Identifier: GPL-2.0

arch/x86/mm/kmemcheck/error.h

-/* SPDX-License-Identifier: GPL-2.0 */

arch/x86/mm/kmemcheck/opcode.c

-// SPDX-License-Identifier: GPL-2.0

arch/x86/mm/kmemcheck/opcode.h

-/* SPDX-License-Identifier: GPL-2.0 */

arch/x86/mm/kmemcheck/pte.c

-// SPDX-License-Identifier: GPL-2.0

arch/x86/mm/kmemcheck/pte.h

-/* SPDX-License-Identifier: GPL-2.0 */

arch/x86/mm/kmemcheck/selftest.c

-// SPDX-License-Identifier: GPL-2.0

arch/x86/mm/kmemcheck/selftest.h

-/* SPDX-License-Identifier: GPL-2.0 */

arch/x86/mm/kmemcheck/shadow.h

-/* SPDX-License-Identifier: GPL-2.0 */

include/linux/kmemcheck.h

-/* SPDX-License-Identifier: GPL-2.0 */

mm/kmemcheck.c

-// SPDX-License-Identifier: GPL-2.0

tools/include/linux/kmemcheck.h

-/* SPDX-License-Identifier: GPL-2.0 */