Fix type error in cm_tdbusm_get_vn

This fixes an out-of-bounds stack write on 32-bit architectures.

Submitted upstream: <https://pagure.io/certmonger/pull-request/265>

diff --git a/src/tdbusm.c b/src/tdbusm.c
index 5e3341172398051d..8f2383dc62bef75e 100644
--- a/src/tdbusm.c
+++ b/src/tdbusm.c
@@ -223,7 +223,7 @@ cm_tdbusm_get_vn(DBusMessage *msg, void *parent, long *n)
 {
 	DBusError err;
 	DBusMessageIter iter, sub_iter;
-	int64_t *i64;
+	int64_t i64;
 
 	dbus_error_init(&err);