KVM: x86: VMX: redo fix for link error without CONFIG_HYPERV

Arnd had sent this patch to the KVM mailing list, but it slipped through
the cracks of maintainers hand-off, and therefore wasn't included in
the pull request.

The same issue had been fixed by Linus in commit dbee3d0 ("KVM: x86:
VMX: fix build without hyper-v", 2018-06-12) as a self-described
"quick-and-hacky build fix".  However, checking the compile-time
configuration symbol with IS_ENABLED is cleaner and it is enough to
avoid the link error, so switch to Arnd's solution.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[Rewritten commit message. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -4429,16 +4429,14 @@ static int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
 			goto out_vmcs;
 		memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);
 
-#if IS_ENABLED(CONFIG_HYPERV)
-		if (static_branch_unlikely(&enable_evmcs) &&
+		if (IS_ENABLED(CONFIG_HYPERV) &&
+		    static_branch_unlikely(&enable_evmcs) &&
 		    (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
 			struct hv_enlightened_vmcs *evmcs =
 				(struct hv_enlightened_vmcs *)loaded_vmcs->vmcs;
 
 			evmcs->hv_enlightenments_control.msr_bitmap = 1;
 		}
-#endif
-
 	}
 	return 0;