mtrr: fix UP breakage caused during switch to stop_machine

While removing custom rendezvous code and switching to stop_machine,
commit 192d885 ("x86, mtrr: use stop_machine APIs for doing MTRR
rendezvous") completely dropped mtrr setting code on !CONFIG_SMP
breaking MTRR settting on UP.

Fix it by removing the incorrect CONFIG_SMP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Anders Eriksson <aeriksson@fastmail.fm>
Tested-and-acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/cpu/mtrr/main.c

@@ -149,7 +149,6 @@ struct set_mtrr_data {
  */
 static int mtrr_rendezvous_handler(void *info)
 {
-#ifdef CONFIG_SMP
 	struct set_mtrr_data *data = info;
 
 	/*
@@ -171,7 +170,6 @@ static int mtrr_rendezvous_handler(void *info)
 	} else if (mtrr_aps_delayed_init || !cpu_online(smp_processor_id())) {
 		mtrr_if->set_all();
 	}
-#endif
 	return 0;
 }