x86,percpu: fix inverted NUMA test in setup_pcpu_remap()

setup_percpu_remap() is for NUMA machines yet it bailed out with
-EINVAL if pcpu_need_numa().  Fix the inverted condition.

This problem was reported by David Miller and verified by Yinhai Lu.

Reported-by: David Miller <davem@davemloft.net>
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <49D30469.8020006@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>