x86: use cpumask function for present, possible, and online cpus

cpu_online(), cpu_present(), for_each_possible_cpu(), num_possible_cpus()

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/genapic_64.c b/arch/x86/kernel/genapic_64.c
index 9546ef4..021624c 100644
--- a/arch/x86/kernel/genapic_64.c
+++ b/arch/x86/kernel/genapic_64.c
@@ -51,7 +51,7 @@
 	else
 #endif
 
-	if (cpus_weight(cpu_possible_map) <= 8)
+	if (num_possible_cpus() <= 8)
 		genapic = &apic_flat;
 	else
 		genapic = &apic_physflat;