efi_loader: avoid #ifdef in efi_setup.c

We prefer `if` over `#ifdef` in our code.

Eliminate #ifdef statements in efi_setup.c.

Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index a610e03..aa59bc7 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -86,7 +86,6 @@
 	return ret;
 }
 
-#ifdef CONFIG_EFI_SECURE_BOOT
 /**
  * efi_init_secure_boot - initialize secure boot state
  *
@@ -112,12 +111,6 @@
 
 	return ret;
 }
-#else
-static efi_status_t efi_init_secure_boot(void)
-{
-	return EFI_SUCCESS;
-}
-#endif /* CONFIG_EFI_SECURE_BOOT */
 
 /**
  * efi_init_capsule - initialize capsule update state
@@ -302,9 +295,11 @@
 	}
 
 	/* Secure boot */
-	ret = efi_init_secure_boot();
-	if (ret != EFI_SUCCESS)
-		goto out;
+	if (IS_ENABLED(CONFIG_EFI_SECURE_BOOT)) {
+		ret = efi_init_secure_boot();
+		if (ret != EFI_SUCCESS)
+			goto out;
+	}
 
 	/* Indicate supported runtime services */
 	ret = efi_init_runtime_supported();
@@ -322,11 +317,11 @@
 		if (ret != EFI_SUCCESS)
 			goto out;
 	}
-#ifdef CONFIG_NETDEVICES
-	ret = efi_net_register();
-	if (ret != EFI_SUCCESS)
-		goto out;
-#endif
+	if (IS_ENABLED(CONFIG_NETDEVICES)) {
+		ret = efi_net_register();
+		if (ret != EFI_SUCCESS)
+			goto out;
+	}
 	if (IS_ENABLED(CONFIG_ACPI)) {
 		ret = efi_acpi_register();
 		if (ret != EFI_SUCCESS)