kvm: remove redundant registration of BSP's hv_clock area

These days hv_clock allocation is memblock based (i.e. the percpu
allocator is not involved), which means that the physical address
of each of the per-cpu hv_clock areas is guaranteed to remain
unchanged through all its lifetime and we do not need to update
its location after CPU bring-up.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kernel/kvm.c

@@ -417,7 +417,6 @@ void kvm_disable_steal_time(void)
 #ifdef CONFIG_SMP
 static void __init kvm_smp_prepare_boot_cpu(void)
 {
-	WARN_ON(kvm_register_clock("primary cpu clock"));
 	kvm_guest_cpu_init();
 	native_smp_prepare_boot_cpu();
 	kvm_spinlock_init();

arch/x86/kernel/kvmclock.c

@@ -242,7 +242,7 @@ void __init kvmclock_init(void)
 	hv_clock = __va(mem);
 	memset(hv_clock, 0, size);
 
-	if (kvm_register_clock("boot clock")) {
+	if (kvm_register_clock("primary cpu clock")) {
 		hv_clock = NULL;
 		memblock_free(mem, size);
 		return;