Fix remaining 32-bit compile issues

Change-Id: I9664214652229b663c3e3ba7406b4ede96bfb123
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vnet/devices/virtio/vhost-user.c b/src/vnet/devices/virtio/vhost-user.c
index acc7bf8..6ccc0d8 100644
--- a/src/vnet/devices/virtio/vhost-user.c
+++ b/src/vnet/devices/virtio/vhost-user.c
@@ -719,7 +719,7 @@
     }
   if (is_host_address)
     {
-      addr = (u64) map_user_mem (vui, (uword) addr);
+      addr = pointer_to_uword (map_user_mem (vui, (uword) addr));
     }
   if (PREDICT_FALSE ((addr + len - 1) / VHOST_LOG_PAGE / 8 >= vui->log_size))
     {