x86, reboot: Fix typo in nmi reboot path

It was brought to my attention that my x86 change to use NMI in
the reboot path broke Intel Nehalem and Westmere boxes when
using kexec.

I realized I had mistyped the if statement in commit
3603a2512f9e69dc87914ba922eb4a0812b21cd6 and stuck the ')' in
the wrong spot.  Putting it in the right spot fixes kexec again.

Doh.

Reported-by: Yinghai Lu <yinghai@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1325866671-9797-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/smp.c

@@ -176,7 +176,7 @@ static void native_nmi_stop_other_cpus(int wait)
 	 */
 	if (num_online_cpus() > 1) {
 		/* did someone beat us here? */
-		if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id() != -1))
+		if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
 			return;
 
 		if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,