Architectures other than mips and x86 are not using ticket spinlocks.
Therefore, the contention on the lock is meaningless, since there is
nobody known to be waiting on it (arguably /fairly/ unfair locks).

Dummy it out to return 0 on other architectures.
Signed-off-by: NKyle McMartin <kyle@redhat.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>