Build init as C++.

This is just the minimal change to keep it building.

Change-Id: I245c5b8413a1db114576c81462eb5737f5ffcef2
diff --git a/init/ueventd.h b/init/ueventd.h
index 0a454c5..d12d7fe 100644
--- a/init/ueventd.h
+++ b/init/ueventd.h
@@ -20,16 +20,18 @@
 #include <cutils/list.h>
 #include <sys/types.h>
 
+enum devname_src_t {
+    DEVNAME_UNKNOWN = 0,
+    DEVNAME_UEVENT_DEVNAME,
+    DEVNAME_UEVENT_DEVPATH,
+};
+
 struct ueventd_subsystem {
     struct listnode slist;
 
     const char *name;
-    enum {
-        DEVNAME_UNKNOWN = 0,
-        DEVNAME_UEVENT_DEVNAME,
-        DEVNAME_UEVENT_DEVPATH,
-    } devname_src;
     const char *dirname;
+    devname_src_t devname_src;
 };
 
 int ueventd_main(int argc, char **argv);