KVM: x86: Use this_cpu_ptr() instead of per_cpu_ptr(smp_processor_id())

Use this_cpu_ptr() instead of open coding the equivalent in various
user return MSR helpers.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Message-ID: <20240802201630.339306-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: yamahata

arch/x86/kvm/x86.c

@@ -427,8 +427,7 @@ static void kvm_user_return_msr_cpu_online(void)
 
 int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
 {
-	unsigned int cpu = smp_processor_id();
-	struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
+	struct kvm_user_return_msrs *msrs = this_cpu_ptr(user_return_msrs);
 	int err;
 
 	value = (value & mask) | (msrs->values[slot].host & ~mask);
@@ -450,8 +449,7 @@ EXPORT_SYMBOL_GPL(kvm_set_user_return_msr);
 
 static void drop_user_return_notifiers(void)
 {
-	unsigned int cpu = smp_processor_id();
-	struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
+	struct kvm_user_return_msrs *msrs = this_cpu_ptr(user_return_msrs);
 
 	if (msrs->registered)
 		kvm_on_user_return(&msrs->urn);