greybus: interface: use an enum for interface type

Use an enum for the interface type instead of using the SVC protocol
values directly.

Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sandeep Patil <sspatil@google.com>
Reviewed-by: Patrick Titiano <ptitiano@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/module.c b/drivers/staging/greybus/module.c
index 242be49..3ae5876 100644
--- a/drivers/staging/greybus/module.c
+++ b/drivers/staging/greybus/module.c
@@ -153,7 +153,7 @@
 			break;
 	}
 	if (ret) {
-		if (intf->type != GB_SVC_INTF_TYPE_DUMMY) {
+		if (intf->type != GB_INTERFACE_TYPE_DUMMY) {
 			dev_err(&module->dev,
 					"failed to activate interface %u: %d\n",
 					intf_id, ret);