dev: fix null dereference of arg list

Type: fix
Fixes: 69768d9
Change-Id: Iafd3a55634583f2799a81c477ccbf5e53b6f29d0
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vnet/dev/api.c b/src/vnet/dev/api.c
index 260bc7b..72811f5 100644
--- a/src/vnet/dev/api.c
+++ b/src/vnet/dev/api.c
@@ -90,9 +90,10 @@
     }
   dev->description = dev_desc;
 
-  for (vnet_dev_arg_t *a = driver->registration->args;
-       a->type != VNET_DEV_ARG_END; a++)
-    vec_add1 (dev->args, *a);
+  if (driver->registration->args)
+    for (vnet_dev_arg_t *a = driver->registration->args;
+	 a->type != VNET_DEV_ARG_END; a++)
+      vec_add1 (dev->args, *a);
 
   if (args->args)
     {