KVM: use lockless __emulator_write_phys in kvm_hypercall_mmu_write()

Index: kvm.paravirt2/arch/x86/kvm/x86.c
===================================================================
@@ -2400,7 +2400,7 @@ static int kvm_hypercall_mmu_write(struc
 			bytes = 4;
 	}
 
-	if (!emulator_write_phys(vcpu, addr, &value, bytes))
+	if (!__emulator_write_phys(vcpu, addr, &value, bytes))
 		return -KVM_EFAULT;
 
 	return 0;